Tire, and tire manufacturing method

ABSTRACT

Provided is a tire having at least a circular tire frame formed of a thermoplastic resin material, the tire including a reinforcing cord member that forms a reinforcing cord layer on the outer circumference of the tire frame, and the thermoplastic resin material including at least a polyamide-based thermoplastic elastomer.

This is a divisional of U.S. application Ser. No. 13/818,531 filed Apr.17, 2013, which is a national stage of PCT/JP2011/069223 filed Aug. 25,2011, which claims priority from Japanese Application Nos. 2010-188903,filed Aug. 25, 2010; 2010-188915, filed Aug. 25, 2010; 2010-188900,filed Aug. 25, 2010; 2010-188901, filed Aug. 25, 2010; 2010-188923,filed Aug. 25, 2010; 2010-188902, filed Aug. 25, 2010; 2010-188922,filed Aug. 25, 2010; 2010-188918, filed Aug. 25, 2010; 2010-188919,filed Aug. 25, 2010; 2010-203732, filed Sep. 10, 2010; 2010-203676,filed Sep. 10, 2010; 2010-258040, filed Nov. 18, 2010; 2010-258041,filed Nov. 18, 2010; and 2011-183311 filed Aug. 25, 2011, the contentsof all of which are hereby incorporated by reference into thisapplication.

TECHNICAL FIELD

The present invention relates to a tire for being fitted on the rim, andmore particularly, to a tire in which at least a portion is formed of athermoplastic material, and a method for producing the same.

BACKGROUND ART

Conventionally, in vehicles such as passenger cars, pneumatic tiresconstructed from rubber, organic fiber materials, steel members, and thelike have been used.

In recent years, an investigation is conducted to use resin materials,particularly thermoplastic resins and thermoplastic elastomers as thetire materials, in view of weight reduction, ease of molding, and easyrecycling.

For example, Japanese Patent Application Publication (JP-A) No.2003-104008 and JP-A No. 03-143701 disclose pneumatic tires formed byusing thermoplastic polymer materials.

In JP-A No. 03-143701, a reinforcing layer in which a reinforcing cordis helically wound continuously in the circumferential direction of thetire is provided on the outer surface in the tire radial direction atthe tread bottom of the tire main body (tire frame), to improve theresistance to cutting or resistance to puncture of the tire main body.

DISCLOSURE OF INVENTION Technical Problem

Tires that in which a thermoplastic polymer material is used can beproduced easily and inexpensively compared to the conventional tiresmade of rubber. However, when the tire frame is formed of a uniformthermoplastic polymer material which is not equipped with a reinforcingmember such as a carcass ply, there is room for improvement from theviewpoint of the resistance to stress, internal pressure and the like,compared to the conventional tires made of rubber (see, for example,JP-A No. 2003-104008).

Furthermore, conventional rubber tires cannot be easily recycled, andrecycling applications thereof are limited, for example, incineratingthe tires, or crushing the tires to be used in the material for roadpavement. On the other hand, tires in which a thermoplastic polymermaterial is used have an advantage that the degree of freedom of theapplications is high, even from the viewpoint of recycling.

In JP-A No. 03-143701, a reinforcing layer in which a reinforcing cordis helically wound continuously in the circumferential direction of thetire is provided on the outer surface in the tire radial direction ofthe tread bottom of the tire main body (tire frame) to improve theresistance to cutting or the resistance to puncture of the tire mainbody. However, when a reinforcing layer in which a reinforcing cord ishelically wound directly around a tire frame formed of a thermoplasticpolymer material, is formed, and a tread is formed on the outer side inthe radial direction of the reinforcing layer, even though an adhesiveis used for the reinforcing cord, it cannot be said that sufficientadhesiveness is provided, and there may be air remaining around thereinforcing cords. As such, if air remains around the reinforcing cord,the reinforcing cord may move at the time of driving and causedetachment between the members. Thus, there is room for an improvementfrom the viewpoint of the durability of tires. Furthermore, since theregion around the reinforcing cord is all covered with a cushion rubber,detachment of the reinforcing cord and the like may occur as a result ofthe difference in the hardness of materials between the tire main bodyand the region around the reinforcing cord.

Also, when a tire is produced by using a thermoplastic polymer material,it is demanded to realize a performance (required characteristics of thetire) that is comparable to that of the conventional rubber tires, whilerealizing low cost by increasing the production efficiency. For example,when a thermoplastic resin material is used as the material for a tireframe, it can be considered, from the viewpoint of production efficiencyand the like, to form the tire frame by injecting a polymer materialinto a mold by injection molding as described in JP-A No. 03-143701.Accordingly, as the thermoplastic polymer material, it is desirable toselect a material which is excellent in the durability obtainable whenthe material is produced into a tire, and in the handleability at thetime of molding (manufacturability) (first, third, fourth, and seventhto thirteenth aspects of the present invention as described below).

Furthermore, for example, a tire is required to have strong resistanceto impact; however, it is requested that tires formed by using athermoplastic polymer material also have impact resistance that is equalto or higher than the impact resistance of conventional tires made ofrubber (second aspect of the present invention as described below).

Furthermore, regarding the characteristics required of tires, forexample, factors such as having an elastic modulus in a certain range,having a low dynamic loss factor at 30° C., 20 Hz and a shear strain of1% (coefficient of rolling: tan δ (hereinafter, may be simply referredto as “tan δ”)), having excellent heat resistance, and the likerespectively constitute important characteristics. However, decrease inthe tan δ value and increase in the elastic modulus in a polymermaterial are usually in a contradictory relationship. Accordingly, it isdesired to develop a tire which can achieve a good balance between thesecharacteristics at a high level (fifth aspect of the present inventionas described below).

Also, on the other hand, use of a thermoplastic resin material in a tiretends to further increase the electrostatic property of the tiresurface. Since electrostatic charging of a tire may cause the occurrenceof discharge, and adhesion of fine dust and the like to the tiresurface, a tire in which a thermoplastic resin material is used andwhich has a superior antistatic ability is desired. However, no suchtire has been provided yet (sixth aspect as described below).

The present invention was achieved in view of the various circumstancesdescribed above.

An object according to a first aspect of the present invention is toprovide a tire which is formed using a thermoplastic polymer materialand exhibits excellent durability and manufacturability.

An object according to a second aspect of the present invention is toprovide a tire which is formed using a thermoplastic polymer materialand exhibits excellent durability, manufacturability and impactresistance.

An object according to a third aspect of the present invention is toprovide a tire which is formed using a thermoplastic resin material andhas excellent tensile elasticity and fracture properties, and a methodfor producing this tire.

An object according to a fourth aspect of the present invention is toprovide a tire which is formed using a thermoplastic resin material andexhibits excellent steering stability with small rolling resistance.

An object according to a fifth aspect of the present invention is toprovide a tire which is formed using a thermoplastic polymer material,is highly elastic, has a low loss factor, and exhibits excellent heatresistance.

An object according to a sixth aspect of the present invention is toprovide a tire which is formed using a thermoplastic resin material andhas an excellent antistatic performance.

An object according to a seventh aspect of the present invention is toprovide a tire which is formed using a thermoplastic resin material, andin which even if the elastic modulus is increased, an increase inrolling resistance can be suppressed.

An object according to an eighth aspect of the present invention is toprovide a tire which is formed using a resin material, and in which anelastic modulus in a suitable range can be obtained and an increase inrolling resistance can be suppressed.

An object according to a ninth aspect of the present invention is toprovide a tire which is formed using a resin material and in whichimpact resistance can be enhanced.

An object according to a tenth aspect of the present invention is toprovide a tire which is formed using a thermoplastic resin material, hashigh durability at the time of driving since air is prevented fromremaining in a region around the reinforcing cord member, and is noteasily affected by temperature change.

An object according to an eleventh aspect of the present invention is toprovide a tire which is formed using a thermoplastic resin material andhas excellent impact resistance, and in which the temperature dependencyof the tensile yield strength is suppressed.

An object according to a twelfth aspect of the present invention is toprovide a tire which is formed using a thermoplastic resin material andhas excellent impact resistance and fracture properties, and a methodfor producing a tire with excellent productivity.

An object according to a thirteenth aspect of the present invention isto provide a tire which is formed using a thermoplastic resin material,and has excellent impact resistance since air is prevented fromremaining in a region around the reinforcing cords.

Solution to Problem

The means for solving the problem of the first aspect is as follows.

(1-1) The tire of the first aspect of the present invention is a tireincluding at least a circular tire frame formed of a thermoplastic resinmaterial, in which the tire includes a reinforcing cord member thatforms a reinforcing cord layer on the outer circumference of the tireframe, and the thermoplastic resin material includes at least apolyamide-based thermoplastic elastomer.

The reinforcing cord layer may be wound around the outer circumferenceof the tire frame in the circumferential direction, or may also be woundaround the outer circumference in a crossing manner.

The tire of the first aspect of the present invention includes acircular tire frame formed of a thermoplastic resin material including apolyamide-based thermoplastic elastomer. The “polyimide-basedthermoplastic elastomer” means a thermoplastic resin material which isformed of a copolymer including a polymer constituting a hard segmentthat is crystalline and has a high melting point, and a polymerconstituting a soft segment that is non-crystalline and has a low glasstransition temperature, and which has an amide bond (—CONH—) in the mainchain of the polymer constituting the hard segment.

Furthermore, the “thermoplastic resin” means a resin havingthermoplasticity, and does not encompass conventional vulcanized rubberssuch as natural rubber or synthetic rubbers. Polyamide-basedthermoplastic elastomers have an advantage that when used as a materialfor forming tire frames, the elastomers have heat resistance and alsoexhibit excellent tensile modulus of elasticity, tensile strength andfracture strain. Also, when a thermoplastic resin material including apolyamide-based thermoplastic elastomer is used in a tire frame, thestructure of the tire can be simplified as compared with theconventional tires made of rubber, and as a result, weight reduction ofthe tire can be realized. Therefore, when a tire frame is formed usingthe thermoplastic resin material, the abrasion resistance and durabilityof the tire can be enhanced. In addition, since a thermoplastic resinmaterial including a polyamide-based thermoplastic elastomer can havethe melting point set to near 100° C. to 250° C., it is easy to handlethe resin material, and energy consumption at the time of forming a tireframe can be suppressed, while productivity can be increased.

In an embodiment of the tire of the first aspect of the presentinvention, the reinforcing cord member is wound around the outercircumference of a tire frame formed of a thermoplastic resin materialincluding a polyamide-based thermoplastic elastomer, and thus areinforcing cord layer is formed. When a reinforcing cord layer isformed on the outer circumference of the tire frame, the resistance topuncture and resistance to cutting of the tire, and the rigidity in thecircumferential direction of the tire (tire frame) are increased. Also,as the rigidity in the circumferential direction is increased, creeping(a phenomenon in which plastic deformation of the tire frame increaseswith time under a constant stress) in the tire frame formed of athermoplastic material is suppressed.

Furthermore, a polyamide-based thermoplastic elastomer can easilypenetrate not only between the fibers of the reinforcing cord memberitself, but also between twisted cords in the case where the reinforcingcord member has a twisted-fiber structure, due to the low melt viscosityof the elastomer. Accordingly, the polyamide-based thermoplasticelastomer has high adhesiveness to reinforcing cord members, and hasexcellent fixing performance such as welding strength. Also, when thereinforcing cord member is an organic fiber, since the polyamide-basedthermoplastic elastomer that forms the tire frame can be welded to thereinforcing cord member, high welding properties and excellent fixingperformance are obtained. Further, since a polyamide-based thermoplasticelastomer exhibits excellent elongation, the fracture properties areexcellent. Therefore, for example, the phenomenon in which air remainsin the region around the reinforcing cord members in the reinforcingcord winding step (incorporation of air) can be suppressed. If thepolyamide-based thermoplastic elastomer has high adhesiveness andwelding properties to the reinforcing cords, and incorporation of airinto the surroundings of the reinforcing cord members is suppressed, themovement of the reinforcing cord members due to, for example, a forceapplied during driving can be effectively suppressed. Thereby, forexample, even in the case where a tire-constituting members is providedso as to cover the entirety of the reinforcing cord members in the outercircumference of the tire frame, since the movement of the reinforcingcord members is suppressed, detachment or the like between these members(including the tire frame) is prevented from occurring, and durabilityof the tire is enhanced.

(1-2) The tire of the first aspect of the present invention can beconfigured such that the reinforcing cord layer contains a resinmaterial. As such, when the reinforcing cord layer contains a resinmaterial, the difference in hardness between the tire and thereinforcing cord layer can be decreased as compared with the case wherethe reinforcing cord member is fixed with a cushion rubber, andtherefore, the reinforcing cord member can be adhered and fixed to thetire frame further. Thereby, the incorporation of air as described abovecan be effectively prevented, and the movement of the reinforcing cordmember at the time of driving can be effectively suppressed.Furthermore, when the reinforcing cord member is a steel cord, if anattempt is made to separate the reinforcing cords from the cushionrubber at the time of disposal of the tire, while it is difficult toseparate a vulcanized rubber from the reinforcing cord only by heating,a resin material can be separated from the reinforcing cord member byheating only. Therefore, it is advantageous in view of recyclability ofthe tire. Furthermore, a resin material usually has a lower loss factor(tan δ) compared to vulcanized rubbers. Accordingly, if the reinforcingcord layer contains a large amount of a resin material, the rollingproperties of the tire can be enhanced. Moreover, a resin having arelatively high elastic modulus compared to vulcanized rubbers isadvantageous in that the resin has high in-plane shear rigidity, andalso exhibits excellent steering stability at the time of tire driving,and excellent abrasion resistance.

In regard to the first aspect of the present invention, if theexpression “resin” is used alone, the “resin” is a concept whichencompasses thermoplastic resins (including thermoplastic elastomers)and thermosetting resins, and does not encompass vulcanized rubbers.

When the reinforcing cord layer contains a resin material, from theviewpoint of increasing the pull-out properties (difficulty to be pulledout) of the reinforcing cords, the reinforcing cord members arepreferably covered by a resin material over 20% or more of the surface,and more preferably 50% or more of the surface. Also, the content of theresin material in the reinforcing cord layer is preferably 20 mass % ormore, and more preferably 50 mass % or more, relative to the totalamount of the materials that constitute the reinforcing cord layerexcluding the reinforcing cords, from the viewpoint of increasing thepull-out properties of the reinforcing cord.

In order to configure the reinforcing cord layer to include a resinmaterial, for example, the reinforcing cord layer can be formed in aconfiguration such that when viewed from a cross-section of the tireframe along the axial direction, at least a portion of the reinforcingcord member is embedded in the outer circumference of the tire framethat is formed of a thermoplastic resin material. In this case, thethermoplastic resin material including a polyamide-based thermoplasticelastomer of the outer circumference of the tire frame in which thereinforcing cord member is embedded corresponds to the resin material asa component of the reinforcing cord layer, and the polyamide-basedthermoplastic elastomer (thermoplastic resin material) forming the tireframe and the reinforcing cord member constitute the reinforcing cordlayer. Furthermore, in order to configure the reinforcing cord layer toinclude a resin material, a coated cord member obtained by coating areinforcing cord with a resin material of the same kind as or adifferent from the resin material that forms the tire frame, may bewound in the circumferential direction of the tire frame. The “samekind” as used for resin material means a situation in which both areester-based resin materials, or both are styrene-based resin materials,or the like.

(1-3) The tire of the first aspect of the present invention can beconfigured such that the melting point of the thermoplastic resinmaterial including a polyamide-based thermoplastic elastomer is 100° C.to 250° C. As such, when the melting point of the thermoplastic resinmaterial including a polyamide-based thermoplastic elastomer is adjustedto 100° C. to 250° C., a balance can be achieved between durability asthe tire performance, and manufacturability in view of reducing theproduction cost.

(1-4) The tire of the first aspect of the present invention can beconfigured such that the content ratio of the polyamide-basedthermoplastic elastomer in the thermoplastic resin material is 50 mass %to 100 mass %. When the content of the polyamide-based thermoplasticelastomer in the thermoplastic resin material is 50 mass % to 100 mass%, the performance of the polyamide-based thermoplastic elastomer can besufficiently exhibited, and a balance can be achieved between durabilityas the tire performance, and handleability or manufacturability in viewof reducing the production cost.

The tire of the first aspect of the present invention can be produced bya production method which includes a tire frame piece forming step offorming a tire frame piece for constituting a portion of a circular tireframe. using a thermoplastic resin material including at least apolyamide-based thermoplastic elastomer; a tire frame piece bonding stepof forming the tire frame by fusing two or more of the tire framepieces, which make a pair, by applying heat to bonding surfaces of thetire frame pieces; and a reinforcing cord member winding step of windinga reinforcing cord members around the outer circumference of the tireframe in the circumferential direction to form a reinforcing cord layer.

In the production method described above, tire frame pieces of thecircular tire frame are formed using a thermoplastic resin materialincluding a polyamide-based thermoplastic elastomer. Since thepolyamide-based thermoplastic elastomer can have its melting point setto about 100° C. to 250° C., for example, it is not necessary to carryout a process of fusing the tire frame pieces at or above 300° C., andthe process of fusing can be carried out at a relatively lowtemperature. As such, since the process of fusing can be carried out ata relatively low temperature, from the viewpoint of energy availabilityor the like, the tire productivity can be increased. Furthermore, whentire frame pieces in which a thermoplastic resin material including apolyamide-based thermoplastic elastomer are fused to form a tire frame,sufficient adhesive strength between the tire frame pieces can beobtained, and the performance of the frame itself is not deteriorated bythe temperature at the time of fusion. Therefore, durability at the timeof driving, such as the resistance to puncture or abrasion resistance ofthe tire thus produced can be increased.

The production method can be configured such that in the tire framepiece bonding step, the bonding surface of the tire frame piece isheated to a temperature equal to or higher than the melting point of thethermoplastic resin material that constitutes the tire frame piece (forexample, melting point +10° C. to +150° C.).

As such, when the bonding surface of the divided body is heated to atemperature higher than or equal to the melting point of thethermoplastic resin material that constitutes the tire frame piece,since fusion between the tire frame pieces can be sufficiently achieved,productivity of the tire can be increased, while durability of the tireis enhanced.

The means for solving the problem of the second aspect is as follows.

(2-1) The tire of the second aspect of the present invention is a tireincluding at least a circular tire frame formed of a thermoplastic resinmaterial, in which the tire includes a reinforcing cord member thatforms a reinforcing cord layer on the outer circumference of the tireframe, and the thermoplastic resin material includes at least apolyamide-based thermoplastic elastomer and an elastomer other than thepolyamide-based thermoplastic elastomer (hereinafter, referred to as“other elastomer” in relation to the second embodiment of the presentinvention).

The reinforcing cord layer may be wound in the circumferential directionof the outer circumference of the tire frame, or may be wound around theouter circumference in a crossing manner.

The tire of the second aspect of the present invention includes acircular tire frame formed of a thermoplastic resin material including apolyamide-based thermoplastic elastomer and another elastomer. Here, the“polyamide-based thermoplastic elastomer” has the same definition asthat used in the first aspect of the present invention as describedabove.

The other elastomer means a thermoplastic resin material formed of acopolymer including a polymer constituting a hard segment that iscrystalline and has a high melting point, or a hard segment that hashigh cohesive force, and a polymer constituting a soft segment that isnon-crystalline and has a low glass transition temperature, in which thepolymer constituting the hard segment is a polymer other than apolyamide having amide bonds (—CONH—) in the main chain, for example, apolyurethane-based thermoplastic elastomer, a polyolefin-basedthermoplastic elastomer (including an olefin copolymer such as anolefin-methacrylic acid copolymer or an olefin-acrylate copolymer), apolystyrene-based thermoplastic elastomer, a polyester-basedthermoplastic elastomer and the like obtainable by polymerizingurethane, styrene, an olefin, and a polyester, respectively. Thethermoplastic resin for the second aspect of the present invention hasthe same definition as that used in the present invention according tothe first aspect as described above. A thermoplastic resin materialincluding a polyamide-based thermoplastic elastomer and anotherelastomer has heat resistance and also exhibits excellent tensilemodulus of elasticity, tensile strength and fracture strain.Furthermore, when a thermoplastic resin material including apolyamide-based thermoplastic elastomer and another elastomer is used inthe tire frame, the structure of the tire can be simplified as comparedto the conventional rubber tires, and as a result, weight reduction ofthe tire can be realized. Therefore, when a tire frame is formed usingthe thermoplastic resin material, abrasion resistance and durability ofthe tire can be increased. On the other hand, in the case where apolyamide-based thermoplastic elastomer is used alone, when an attemptis made to adjust the elastic modulus, it is necessary to control theratio of the hard segment and the soft segment. On the contrary, when apolyamide-based thermoplastic elastomer and another elastomer are usedin combination, the elastic modulus of the thermoplastic resin materialcan be easily adjusted by adjusting the content ratio of the twocomponents, as compared to the case of using a polyamide-basedthermoplastic elastomer alone. Therefore, since the elastic modulus ofthe thermoplastic resin material can be easily set to a desired range,the resin material is excellent in view of the production cost, andimpact resistance can be easily enhanced.

In an embodiment of the tire of the second aspect of the presentinvention, a reinforcing cord member is wound around the outercircumference of a tire frame formed of a thermoplastic resin materialincluding a polyamide-based thermoplastic elastomer and anotherelastomer, to form a reinforcing cord layer. When the reinforcing cordlayer is formed on the outer circumference of the tire frame, theresistance to puncture and resistance to cutting of the tire, and therigidity in the circumferential direction of the tire (tire frame) areincreased. Also, as the rigidity in the circumferential direction isincreased, creeping (a phenomenon in which plastic deformation of thetire frame increases with time under a constant stress) in the tireframe formed of a thermoplastic material is suppressed.

Furthermore, a polyamide-based thermoplastic elastomer can easilypenetrate not only between the fibers of the reinforcing cord memberitself, but also between twisted cords in the case where the reinforcingcord member has a twisted-fiber structure, due to the low melt viscosityof the elastomer. Accordingly, the polyamide-based thermoplasticelastomer has high adhesiveness to reinforcing cord member, and hasexcellent fixing performance such as welding strength. Also, when thereinforcing cord member is an organic fiber, since the polyamide-basedthermoplastic elastomer that forms the tire frame can be welded to thereinforcing cord member, high welding properties and excellent fixingperformance are obtained. Further, since a polyamide-based thermoplasticelastomer exhibits excellent elongation, the fracture properties areexcellent. Therefore, when a thermoplastic resin material including apolyamide-based thermoplastic elastomer and another elastomer is used,for example, the phenomenon in which air remains in the surroundings ofthe reinforcing cord members in the reinforcing cord winding step(incorporation of air) can be suppressed. If the thermoplastic resinmaterial has high adhesiveness and welding properties to the reinforcingcord, and incorporation of air into the surroundings of the reinforcingcord members is suppressed, the movement of the reinforcing cord memberdue to, for example, a force applied during driving can be effectivelysuppressed. Thereby, for example, even in the case where atire-constituting member is provided so as to cover the entirety of thereinforcing cord members in the outer circumference of the tire frame,since the movement of the reinforcing cord members is suppressed,detachment or the like between these members (including the tire frame)is prevented from occurring, and durability of the tire is enhanced.

(2-2) The tire of the second aspect of the present invention can beconfigured such that the reinforcing cord layer contains a resinmaterial. As such, when the reinforcing cord layer contains a resinmaterial, the difference in hardness between the tire and thereinforcing cord layer can be decreased as compared with the case wherethe reinforcing cord members are fixed with a cushion rubber, andtherefore, the reinforcing cord members can be adhered and fixed to thetire frame further. Thereby, the incorporation of air as described abovecan be effectively prevented, and the movement of the reinforcing cordmember at the time of driving can be effectively suppressed.Furthermore, when the reinforcing cord member is a steel cord, if anattempt made to separate the reinforcing cord from the cushion rubber atthe time of disposal of the tire, while it is difficult to separate avulcanized rubber from the reinforcing cord only by heating, a resinmaterial can be separated from the reinforcing cord member by heatingonly. Therefore, it is advantageous in view of recyclability of thetire. Furthermore, a resin material usually has a lower loss factor (tanδ) compared to vulcanized rubbers. Accordingly, if the reinforcing cordlayer contains a large amount of a resin material, the rollingproperties of the tire can be enhanced. Moreover, a resin having arelatively high elastic modulus compared to vulcanized rubbers isadvantageous in that the resin has high in-plane shear rigidity, andalso exhibits excellent steering stability at the time of tire driving,and excellent abrasion resistance.

Here, if the expression “resin” is used alone, the “resin” has the samedefinition as that used in the first aspect of the present inventiondescribed above.

When the reinforcing cord layer contains a resin material, from theviewpoint of increasing the pull-out properties (difficulty to be pulledout) of the reinforcing cords, the reinforcing cord members arepreferably covered by a resin material over 20% or more of the surface,and more preferably 50% or more of the surface. Also, the content of theresin material in the reinforcing cord layer is preferably 20 mass % ormore, and more preferably 50 mass % or more, relative to the totalamount of the materials that constitute the reinforcing cord layerexcluding the reinforcing cords, from the viewpoint of increasing thepull-out properties of the reinforcing cords.

In order to configure the reinforcing cord layer to include a resinmaterial, for example, the reinforcing cord layer can be formed in aconfiguration such that when viewed from a cross-section of the tireframe along the axial direction, at least a portion of the reinforcingcord member is embedded in the outer circumference of the tire framethat is formed of a thermoplastic resin material. In this case, thethermoplastic resin material including a polyamide-based thermoplasticelastomer and another elastomer in the outer circumference of the tireframe in which the reinforcing cord member is embedded, corresponds tothe resin material as a component of the reinforcing cord layer, and thepolyamide-based thermoplastic elastomer (thermoplastic resin material)forming the tire frame and the reinforcing cord member constitute thereinforcing cord layer. Furthermore, in order to configure thereinforcing cord layer to include a resin material, a coated cord memberobtained by coating a reinforcing cord with a resin material of the samekind as or different from the resin material that forms the tire frame,may be wound in the circumferential direction of the tire frame. The“same kind” as used for resin material means a situation in which bothare ester-based resin materials, or both are styrene-based resinmaterials, or the like.

(2-3) The tire of the second aspect of the present invention can beconfigured such that the mass ratio (x:y) of the polyamide-basedthermoplastic elastomer (x) and the other elastomer (y) in thethermoplastic resin is 95:5 to 60:40. As such, when the mass ratio (x:y)of the polyamide-based thermoplastic elastomer (x) and the otherelastomer (y) is set to 95:5 to 60:40, a good balance can be easilyachieved between the welding properties between the reinforcing cordmembers and the tire frame, and the impact resistance of the tire.

(2-4) The tire of the second aspect of the present invention can beconfigured such that the other elastomer is any one selected from apolyurethane-based thermoplastic elastomer, a polyolefin-basedthermoplastic elastomer, a polystyrene-based thermoplastic elastomer, ofa polyester-based thermoplastic elastomer. When the other elastomer inthe thermoplastic resin material is any one selected from apolyurethane-based thermoplastic elastomer, a polyolefin-basedthermoplastic elastomer, a polystyrene-based thermoplastic elastomer, ora polyester-based thermoplastic elastomer, the performance of thepolyamide-based thermoplastic elastomer can be sufficiently exhibited,and also, a balance between durability and impact resistance of the tirecan be easily achieved.

The tire of the second aspect of the present invention can be producedby a production method which includes a tire frame piece forming step offorming a tire frame piece for constituting a portion of a circular tireframe, using a thermoplastic resin material including at least apolyamide-based thermoplastic elastomer and the another elastomer; atire frame piece bonding step of forming a tire frame by fusing two ormore of the tire frame pieces, which make a pair, by applying heat tobonding surfaces of the tire frame piece; and a reinforcing cord memberwinding step of winding a reinforcing cord member around the outercircumference of the tire frame in the circumferential direction to forma reinforcing cord layer.

In the production method described above, tire frame pieces of thecircular tire frame can be formed by using a thermoplastic resinmaterial including a polyamide-based thermoplastic elastomer and anotherr elastomer. Since the polyamide-based thermoplastic elastomer can haveits melting point set to about 100° C. to 250° C., for example, it isnot necessary to carry out a process of fusing the tire frame pieces ator above 300° C., and the process of fusing can be carried out at arelatively low temperature. As such, since the process of fusing can becarried out at a relatively low temperature, deterioration of the resincan be prevented, and from the viewpoint of energy availability or thelike, the tire productivity can be increased. Furthermore, a tire framepiece in which a thermoplastic resin material including apolyamide-based thermoplastic elastomer and the another elastomer isused is such that when tire frame pieces are fused to form a tire frame,sufficient adhesive strength between the tire frame pieces is obtained,and the performance of the frame itself is not deteriorated by thetemperature at the time of fusion. Therefore, durability at the time ofdriving, such as the resistance to puncture or abrasion resistance ofthe tire thus produced can be increased.

The production method can be configured such that in the tire framepiece bonding step, the bonding surface of the tire frame piece isheated to a temperature equal to or higher than the melting point of thethermoplastic resin material that constitutes the tire frame piece (forexample, melting point +10° C. to +150° C.).

As such, when the bonding surface of the divided body is heated to atemperature higher than or equal to the melting point of thethermoplastic resin material that constitutes the tire frame piece,since fusion between the tire frame pieces can be sufficiently achieved,productivity of the tire can be increased, while durability of the tireis enhanced.

The means for solving the problem of the third aspect is as follows.

(3-1) The tire of the third aspect of the present invention is a tireincluding at least a circular tire frame formed of a thermoplastic resinmaterial, in which the thermoplastic resin material includes apolyamide-based thermoplastic elastomer, and an acid-modified elastomerobtained by acid-modifying a thermoplastic elastomer other than thepolyamide-based thermoplastic elastomer, or a mixture of a thermoplasticelastomer other than the polyamide-based thermoplastic elastomer and anacid-modified elastomer obtained by acid-modifying the elastomer otherthan the polyamide-based thermoplastic elastomer.

That is, the tire of the third aspect of the present invention includesa circular tire frame formed of a specific thermoplastic resin material,and the specific thermoplastic resin material includes at least 1) acombination of a polyamide-based thermoplastic elastomer and anacid-modified elastomer obtained by acid-modifying a thermoplasticelastomer other than the polyamide-based thermoplastic elastomer, or 2)a combination of a polyamide-based thermoplastic elastomer, athermoplastic elastomer other than a polyamide-based thermoplasticelastomer, and an acid-modified elastomer obtained by acid-modifying athermoplastic elastomer other than a polyamide-based thermoplasticelastomer.

Hereinafter, the “thermoplastic elastomer” refers to a thermoplasticresin material formed of a copolymer that includes a polymerconstituting a hard segment that is crystalline and has a high meltingpoint or a hard segment that has high cohesive force power, and apolymer constituting a soft segment that is non-crystalline and has alow glass transition temperature.

The “polyimide-based thermoplastic elastomer” has the same definition asthat used in the first aspect of the present invention as describedabove.

In the third aspect of the present invention, the “thermoplasticelastomer other than a polyamide-based thermoplastic elastomer” means athermoplastic elastomer which does not include an amide bond (—CONH—) inthe main chain of the polymer constituting the hard segment, amongthermoplastic elastomers. Hereinafter, a thermoplastic elastomer otherthan a polyamide-based thermoplastic elastomer will also be referred toas “other thermoplastic elastomer”.

In the third aspect of the present invention, the “acid-modifiedelastomer obtained by acid-modifying a thermoplastic elastomer otherthan a polyamide-based thermoplastic elastomer” means a thermoplasticelastomer obtained by bonding a compound having an acidic group to athermoplastic elastomer other than a polyamide-based thermoplasticelastomer (other thermoplastic elastomer). In addition, the“thermoplastic elastomer other than a polyamide-based thermoplasticelastomer” (other thermoplastic elastomer) does not encompass anacid-modified elastomer obtained by acid-modifying another thermoplasticelastomer.

The thermoplastic resin in the third aspect of the present invention hasthe same definition as that used in the present invention according tothe first aspect as described above.

A polyamide-based thermoplastic elastomer is advantageous in that thethermoplastic elastomer has heat resistance, and also exhibits excellenttensile modulus of elasticity, tensile strength, and fracture strain.Furthermore, as the thermoplastic resin material includes anacid-modified elastomer, since the elasticity of the resin material doesnot become too strong, and the thermoplastic resin material is flexible,the tensile modulus of elasticity can be decreased, and impactresistance can be improved. Furthermore, even if the resin material isfractured, the resin material is not easily torn off and ruptured, andthe resin material easily forms a stretched state. Accordingly,regarding the tire performance, even when the tire is damaged, puncturedoes not easily occur, and rupture of the tire can be avoided.

(3-2) The tire of the third aspect of the present invention can beconfigured such that the acid value of the thermoplastic resin materialis equal to or greater than 0.1 mg-CH₃ONa/g but less than 2.2mg-CH₃ONa/g.

As such, when the acid value of the thermoplastic resin material isadjusted to the range described above, particularly, the melt viscosityof the thermoplastic resin material does not increase excessively, andsince excellent fluidity is obtained, injection molding properties aresuperior. Accordingly, the production efficiency of the tire increases.Therefore, a balance can be achieved between tensile elasticity andfracture properties as the tire performance, and manufacturability inview of the injection molding properties.

The thermoplastic resin material has a sea-island structure having a seaphase, which is a matrix phase formed of a polyamide-based thermoplasticelastomer, and an island phase, which is a dispersed phase formed of anacid-modified elastomer, or an acid-modified elastomer and anotherthermoplastic elastomer (unmodified). In regard to the sea-islandstructure, as the acid value is higher, the island phase tends to besmaller, and as the acid value is lower, the island phase tends to belarger. When the acid value of the acid-modified elastomer is in therange described above, the island phase is finely dispersed in thethermoplastic resin, and impact resistance, tensile elasticity, andfracture properties are enhanced.

(3-3) The tire of the third aspect of the present invention can beconfigured such that the ratio of the mass of the polyamide-basedthermoplastic elastomer in the thermoplastic resin material, and thetotal mass of the acid-modified elastomer and the thermoplasticelastomer other than a polyamide-based thermoplastic elastomer (mass ofthe polyamide-based thermoplastic elastomer:total mass of theacid-modified elastomer and the thermoplastic elastomer other than apolyamide-based thermoplastic elastomer) is from 90:10 to 60:40.

When the ratio of the mass of the polyamide-based thermoplasticelastomer in the thermoplastic resin material in the thermoplastic resinmaterial and the total mass of the acid-modified elastomer and thethermoplastic elastomer other than a polyamide-based thermoplasticelastomer is adjusted to the range described above, the performance ofthe thermoplastic resin material can be sufficiently exhibited, and thetensile elasticity and fracture properties as the tire performance canbe further enhanced.

(3-4) The tire of the third aspect of the present invention can beconfigured such that the content of the polyamide-based thermoplasticelastomer in the thermoplastic resin material is 55 mass % to 95 mass %.

When the content of the polyamide-based thermoplastic elastomer in thethermoplastic resin material is in the range described above, theperformance of the thermoplastic resin material can be sufficientlyexhibited, and the tensile elasticity and fracture properties as thetire performance can be further enhanced.

Furthermore, the tire of the third aspect of the present invention mayalso include, in addition to the tire frame formed of a thermoplasticresin material, a reinforcing cord member that is wound around the outercircumference of the tire frame formed of a thermoplastic resin materialto form a reinforcing cord layer.

When the reinforcing cord member is wound in the circumferentialdirection around the outer circumference of the tire frame formed of athermoplastic resin material to form a reinforcing cord layer, theresistance to puncture and resistance to cutting of the tire, and therigidity in the circumferential direction of the tire (tire frame) areincreased. Meanwhile, as the rigidity in the circumferential directionis increased, creeping (a phenomenon in which plastic deformation of thetire frame increases with time under a constant stress) in the tireframe formed of a thermoplastic material is suppressed.

(3-5) The method for producing a tire of the third aspect of the presentinvention includes a tire frame piece forming step of forming a tireframe piece for constituting a portion of a circular tire frame, using athermoplastic resin material including at least a polyamide-basedthermoplastic elastomer, and an acid-modified elastomer obtained byacid-modifying a thermoplastic elastomer other than the polyamide-basedthermoplastic elastomer, or a mixture of a thermoplastic elastomer otherthan the polyamide-based thermoplastic elastomer and an acid-modifiedelastomer obtained by acid-modifying the elastomer other than thepolyamide-based thermoplastic elastomer; and a tire frame piece bondingstep of forming a tire frame by fusing two or more of the tire framepieces, which make a pair, by applying heat to the bonding surfaces ofthe tire frame pieces.

The method for producing a tire of the third aspect of the presentinvention forms a tire frame piece of a circular tire frame, using athermoplastic resin material. Since the thermoplastic resin material hasexcellent tensile elasticity and fracture properties, the riding qualityof a car using a tire thus produced is excellent, and the resistance tobursting and resistance to puncture of the tire can be enhanced.

(3-6) The method for producing a tire of the third aspect of the presentinvention can be configured such that the acid value of thethermoplastic resin material is equal to or greater than 0.1 mg-CH₃ONa/gbut less than 2.2 mg-CH₃ONa/g.

As such, when the acid value of the thermoplastic resin material isadjusted to the range described above, particularly, the melt viscosityof the thermoplastic resin material does not increase excessively, andsince fluidity is excellent, injection molding properties are superior.Therefore, the production efficiency of the tire increases, and it isalso preferable from an environmental viewpoint such as energy saving.

(3-7) The method for producing a tire of the third aspect of the presentinvention can be configured so as to include a process of performinginjection molding using the thermoplastic resin material in the tireframe piece forming step.

Since a thermoplastic resin material having an acid value of thethermoplastic resin material of equal to or greater than 0.1 mg-CH3ONa/gbut less than 2.2 mg-CH3ONa/g has excellent injection moldingproperties, productivity of the tire can be increased.

The means for solving the problem of the fourth aspect is as follows.

(4-1) The tire of the fourth aspect of the present invention is a tireincluding a circular tire frame formed of a thermoplastic resinmaterial, in which the thermoplastic resin material includes athermoplastic elastomer including a hard segment and a soft segment inthe molecule thereof, and needle-shaped crystal grains having a fiberlength of 1 μm to 500 μm and a fiber diameter of 0.01 μm to 10.0 μm(hereinafter, also appropriately referred to as “specific needle-shapedcrystal grains”).

(4-2) In regard to the tire of the fourth aspect of the presentinvention, it is preferable that the content of the specificneedle-shaped crystal grains relative to the total mass of thethermoplastic resin material that forms the tire frame be in the rangeof 0.1 mass % to 10 mass %.

(4-3) In regard to the tire of the fourth aspect of the presentinvention, it is preferable that the needle-shaped crystal grainscontained in the thermoplastic resin material are inorganic particlesselected from a metal oxide, a metal nitride, a metal carbonate, a metalsilicate, a metal titanate, a metal sulfate, or a metal borate.

(4-4) In regard to the tire of the fourth aspect of the presentinvention, it is preferable that the thermoplastic elastomer included inthe thermoplastic resin material be a thermoplastic elastomer selectedfrom a polyamide-based thermoplastic elastomer, a polyester-basedthermoplastic elastomer, or a polystyrene-based thermoplastic elastomer.

The means for solving the problem of the fifth aspect is as follows.

(5-1) The tire of the fifth aspect of the present invention is a tireincluding at least a circular tire frame formed of a resin material, inwhich the resin material includes a thermoplastic elastomer including ahard segment and a soft segment in the molecule thereof, and a resinhaving a glass transition temperature that is higher than the glasstransition temperature of the hard segment.

The tire of the fifth aspect of the present invention includes acircular tire frame formed of a resin material including a thermoplasticelastomer including a hard segment and a soft segment in the moleculethereof, and a resin having a glass transition temperature (Tg) that ishigher than the glass transition temperature of the hard segment(hereinafter, may be referred to as “specific resin according to thefifth aspect of the present invention”). In regard to the tire of thefifth aspect of the present invention, since the tire frame is formed ofthe resin material, a vulcanization process that is an essential processfor the conventional tires made of rubber is not essential, and the tireframe can be molded by, for example, injection molding. Therefore,simplification of the production process, time shortening, costreduction, and the like can be promoted. Furthermore, when a resinmaterial is used in the tire frame, the structure of the tire can besimplified as compared with the conventional tires made of rubber, andas a result, weight reduction of the tire can be realized. Accordingly,abrasion resistance and durability of the tire in which a tire frame isformed of the time material can be enhanced.

The “thermoplastic elastomer” has the same definition as that used inthe present invention according to the third aspect as described above.In order to increase the elastic modulus of the thermoplastic elastomer(for example, the tensile modulus of elasticity defined in JISK7113:1995), increasing the content ratio of the hard segment in theelastomer may be considered. However, when the content ratio of the hardsegment is increased in order to increase the elastic modulus of thethermoplastic elastomer, the loss factor (tan δ) of the thermoplasticelastomer also increases along therewith.

Furthermore, in order to enhance the heat resistance (temperaturedependency of defletion under load, the elastic modulus, and the like)of the tire frame, using a thermoplastic elastomer having a high glasstransition temperature or a thermoplastic elastomer having a highelastic modulus can be considered. However, as explained above, thesethermoplastic elastomers also undergo an increase in the tan δ value.

In the tire of the fifth aspect of the present invention, the resinmaterial that forms the tire frame includes the specific resin accordingto the fifth aspect of the present invention, which has a glasstransition temperature (Tg) higher than that of the hard segment, inaddition to the thermoplastic elastomer. Therefore, as compared with thecase of using the thermoplastic elastomer as a single substance, anincrease in the elastic modulus can be achieved while the tan δ value ofthe tire frame is maintained low. Thereby, a tire having a low rollingresistance and a high elastic modulus can be provided. Furthermore,since the elastic modulus can be increased while the tan δ value of thetire frame is maintained low, heat resistance of the tire frame can alsobe increased.

(5-2) In regard to the tire of the fifth aspect of the presentinvention, a resin having a glass transition temperature that is higherby 20° C. or more than the glass transition temperature of the hardsegment of the thermoplastic elastomer can be used as the resin. Thetire of the fifth aspect of the present invention can sufficientlyexhibit an effect of increasing the elastic modulus, by adjusting thedifference between the glass transition temperature of the hard segmentof the thermoplastic elastomer and the glass transition temperature ofthe resin, to 20° C. or more.

The difference (Tg₁−Tg₂) between the glass transition temperature of thehard segment (Tg₁) and the glass transition temperature of the specificresin according to the fifth aspect of the present invention (Tg₂) ispreferably 20° C. to 200° C., and more preferably 30° C. to 80° C.

(5-3) In regard to the tire of the fifth aspect of the presentinvention, the mass ratio (x+y:z) of the soft segment (z) of thethermoplastic elastomer with respect to the total amount (x+y) of thehard segment (x) of the thermoplastic elastomer and the resin (y) can beadjusted to 10:90 to 90:10.

When the mass ratio (x+y:z) is in the range of 10:90 to 90:10, theeffect of increasing the elastic modulus while maintaining the tan δvalue of the tire frame low can be sufficiently exhibited.

The mass ratio (x+y:z) is preferably 40:60 to 80:20.

(5-4) The tire of the fifth aspect of the present invention can beconfigured such that the thermoplastic elastomer is at least oneselected from a polyamide-based thermoplastic elastomer or apolyester-based elastomer.

(5-5) The tire of the fifth aspect of the present invention can beconfigured such that the resin is at least one selected frompolyphenylene ether, polyphenylene sulfide, polyethylene terephthalate,polybutylene terephthalate, polyethylene naphthalate, polybutylenenaphthalate, polytrimethylene terephthalate, polycarbonate, andpolyallylate.

Furthermore, regarding the combination of the thermoplastic elastomerand the resin, at least one selected from a combination of apolyamide-based elastomer and polyphenylene ether; a combination of apolyamide-based thermoplastic elastomer and polyphenylene ether; acombination of a polyamide-based thermoplastic elastomer and any one ofpolyphenylene sulfide, polyethylene terephthalate, polybutyleneterephthalate, polyethylene naphthalate, polybutylene naphthalate,polytrimethylene terephthalate, polycarbonate or polyallylate; and acombination of a polyester-based thermoplastic elastomer and any one ofpolyphenylene ether, polyphenylene sulfide, polyethylene terepthalate,polybutylene terephthalate, polyethylene naphthalate, polybutylenenaphthalate, polytrimethylene terephthalate, polycarbonate, orpolyallylate, is preferred.

The means for solving the problem of the sixth aspect is as follows.

(6-1) The tire of the sixth aspect of the present invention is a tireincluding a circular tire frame formed of a thermoplastic resinmaterial, in which the tire frame has a volume resistivity in the rangeof 1.0×10⁶ to 1.0×10¹⁰.

(6-2) In the tire of the sixth aspect of the present invention, it ispreferable that the tire frame include an antistatic material.

(6-3) In the tire of the sixth aspect of the present invention, it ispreferable that the thermoplastic resin material include a thermoplasticelastomer.

(6-4) In the tire of the sixth aspect of the present invention, it ispreferable that the antistatic material be a phosphoric acid ester-basedionic conductor.

The means for solving the problem of the seventh aspect is as follows.

(7-1) The tire of the seventh aspect of the present invention is a tireincluding at least a circular tire frame formed of a thermoplastic resinmaterial, in which the thermoplastic resin material includes athermoplastic elastomer including a hard segment and a soft segment inthe molecule thereof, and a resin of the same kind as the hard segment,which is other than the thermoplastic elastomer.

Here, the “thermoplastic elastomer” is a thermoplastic resin materialincluding a hard segment and a soft segment in the molecule thereof, andhas the same definition as that used in the third aspect of the presentinvention as described above. The “resin of the same kind as the hardsegment” included in the thermoplastic elastomer refers to a resinhaving a skeleton that is common with the skeleton constituting the mainchain of the hard segment included in the thermoplastic elastomer.Meanwhile, the resin in the seventh aspect of the present invention hasthe same definition as that used in the first aspect of the presentinvention as described above. The thermoplastic elastomer also does notencompass conventional vulcanized rubbers such as natural rubber orsynthetic rubbers.

Hereinafter, a resin of the same kind as the hard segment included inthe thermoplastic elastomer, which is other than the thermoplasticelastomer, is also simply referred to as “specific resin according tothe seventh aspect of the present invention”.

When the specific resin according to the seventh aspect of the presentinvention has a skeleton that is common with the skeleton constitutingthe main chain of the hard segment carried by the thermoplasticelastomer, the affinity between the specific resin according to theseventh aspect of the present invention and the hard segment of thethermoplastic elastomer increases. Therefore, as the thermoplastic resinmaterial includes the thermoplastic elastomer of the constitutiondescribed above and the specific resin according to the seventh aspectof the present invention, the specific resin according to the seventhaspect of the present invention is compatible with the hard segment ofthe thermoplastic elastomer and is localized in the hard segment of thethermoplastic elastomer. Thus, the region of the hard segment increases.

Therefore, in a thermoplastic resin containing the specific resinaccording to the seventh aspect of the present invention and athermoplastic elastomer, it is believed that it is not such that simplythe two components are included, and the specific resin according to theseventh aspect of the present invention is uniformly dispersed in thethermoplastic elastomer, and exhibit the respective properties of thespecific resin according to the seventh aspect of the present inventionand the thermoplastic elastomer, but that the elastic modulus of thethermoplastic resin material increases due to increase in the region ofthe hard segment of the thermoplastic elastomer.

Since the rolling resistance of a tire is caused by vibration atapproximately 10 Hz to 100 Hz at near 50° C., when the viscoelasticityof the tire is measured, the magnitude of the rolling resistance can beexpressed by tan δ at 30° C. to 50° C.

A tire formed using a resin material composed only of a thermoplasticelastomer has a tendency that when the number of hard segment regions ofthe thermoplastic elastomer is increased to increase the elasticmodulus, the loss tangent (tan δ) increases. Specifically, when theratio of the hard segment and the soft segment of the thermoplasticelastomer is changed to increase the elastic modulus, the peak of tan δof the thermoplastic elastomer in the measurement of viscoelasticity isshifted to the higher temperature side, and the tan δ value at 30° C. to50° C. tends to increase.

When the loss tangent (tan δ) of the resin material increases, theenergy loss (heat generation) occurring upon deformation at the time oftire rolling tends to increase, and the rolling resistance tends toincrease. Accordingly, a car using a tire which uses such a resinmaterial as a raw material tends to have a large fuel consumption. Thatis, in a tire formed by using a resin material that is composed only ofa thermoplastic elastomer, if the elastic modulus of the resin materialis increased for the purpose of enhancing the resistance to deformationof the tire, the tan δ value of the resin material also increases at thesame time. Therefore, it has been difficult to realize low fuelconsumption.

On the contrary, when a tire frame is produced using the thermoplasticresin material according to the seventh aspect of the present inventionhaving the constitution described above, and thus a tire is formed, evenif the elastic modulus of the thermoplastic resin material increases,the tan δ value does not easily increase. This is thought to be becausewhen the specific resin according to the seventh aspect of the presentinvention is compatible with the hard segment of the thermoplasticelastomer, the region of the hard segment itself increases, and in themeasurement of viscoelasticity, a shift of the peak of tan δ of thethermoplastic resin material is suppressed. As a result, it isspeculated that although a peak of tan δ of the specific resin accordingto the seventh aspect of the present invention appears, the tan δ issuppressed in overall.

Thus, it is thought that in the seventh aspect of the present invention,even though the elastic modulus of the thermoplastic resin materialincreases, the tan δ value does not easily increase.

(7-2) The tire of the seventh aspect of the present invention can beconfigured such that the elastic modulus of the resin is 100 MPa orgreater.

As such, when the elastic modulus of the resin that is easily compatiblewith the hard segment included in the thermoplastic elastomer isadjusted to the range described above, the elastic modulus of the hardsegment of the thermoplastic elastomer can be further increased.Therefore, a thermoplastic resin material having even higher elasticmodulus can be obtained. As a result, a tire having a higher elasticmodulus can be obtained.

(7-3) The tire of the seventh aspect of the present invention can beconfigured such that the mass ratio of the thermoplastic elastomer andthe resin (the thermoplastic elastomer:the resin) is 95:5 to 50:50.

When the content of the thermoplastic elastomer in the thermoplasticresin material is in the range described above, the performance of thethermoplastic resin material can be sufficiently exhibited, and tensilecharacteristics such as tensile elasticity and breaking strength as thetire performance can be enhanced.

(7-4) The tire of the seventh aspect of the present invention can beconfigured such that the content of the thermoplastic elastomer in thethermoplastic resin material is 50 mass % to 95 mass %.

When the content of the thermoplastic elastomer in the thermoplasticresin material is in the range described above, the performance of thethermoplastic resin material can be sufficiently exhibited, and tensilecharacteristics such as tensile elasticity and breaking strength as thetire performance can be further enhanced.

(7-5) It can be configured such that the thermoplastic elastomer is apolyamide-based thermoplastic elastomer, and the resin is apolyamide-based resin.

Here, the “polyimide-based thermoplastic elastomer” has the samedefinition as that used in the first aspect of the present invention asdescribed above. Furthermore, the polyamide-based resin refers to athermoplastic resin including an amide bond (—CONH—) in the main chainthereof.

As such, regarding the specific resin according to the seventh aspect ofthe present invention of the polyamide-based thermoplastic elastomer, itis preferable to use a resin having a skeleton (amide bonds) that iscommon with the skeleton (amide bonds) constituting the main chain ofthe molecular chain of the hard segment included in the polyamide-basedthermoplastic elastomer, that is, a polyamide-based resin. Apolyamide-based thermoplastic elastomer has an advantage that theelastomer has heat resistance, and also exhibits excellent tensilemodulus of elasticity, tensile strength, and fracture strain. Therefore,when a polyamide-based resin is used in combination as the specificresin according to the seventh aspect of the present invention, aneffect of further suppressing rolling resistance can be exhibited, and atire having satisfactory durability and exhibits low fuel consumptioncan be obtained.

Furthermore, the tire of the seventh aspect of the present invention mayfurther include a reinforcing cord member that is wound around the outercircumference of the tire frame formed of the thermoplastic resinmaterial to form a reinforcing cord member layer, in addition to thetire frame formed of a thermoplastic resin material.

When the reinforcing cord member is wound around the outer circumferenceof the tire frame formed of a thermoplastic resin material to form thereinforcing cord member layer, the resistance to puncture, theresistance to cutting of the tire, and the rigidity in thecircumferential direction of the tire (tire frame) are enhanced.Furthermore, as the rigidity in the circumferential direction isincreased, creeping (a phenomenon in which plastic deformation of thetire frame increases with time under a constant stress) in the tireframe formed of a thermoplastic material is suppressed.

The means for solving the problem of the eighth aspect is as follows.

(8-1) The tire of the eighth aspect of the present invention is a tireat least including a circular tire frame formed of a resin material, inwhich the resin material includes at least a thermoplastic elastomer,and a resin which is other than the thermoplastic elastomer, has a glasstransition temperature of 20° C. or lower, and has an elastic modulusgreater than the elastic modulus of the thermoplastic elastomer.

Here, the “thermoplastic elastomer” has the same definition as that usedin the third aspect of the present invention as described above.

Furthermore, the “resin” in the eighth aspect of the present inventionhas the same definition as that used in the present invention accordingto the first aspect as described above. The thermoplastic elastomer alsodoes not encompass conventional vulcanized rubbers such as naturalrubber, or a synthetic rubber.

Hereinafter, a resin which is other than the thermoplastic elastomer,has a glass transition temperature of 20° C. or lower, and has anelastic modulus greater than the elastic modulus of the thermoplasticelastomer, is also simply referred to as a “specific resin according tothe eighth aspect of the present invention.”

When the resin material includes the specific resin according to theeighth aspect of the present invention having a glass transitiontemperature in the range described above, in addition to thethermoplastic elastomer, an increase in rolling resistance can besuppressed.

Regarding a tire formed by using a resin material composed only of athermoplastic elastomer, as the elastic modulus of the resin materialincreases, the energy loss caused by a hysteresis loss occurring upondeformation of the tire increases. Therefore, the rolling resistancetends to be large, and the energy loss (heat generation) also tends toincrease. The rolling resistance of the tire can be estimated from theloss tangent (tan δ) of the material that constitutes the tire, and forexample, as the rolling resistance of the tire increases, the tan δvalue of the material constituting the tire tends to increase.

Furthermore, since rolling resistance of a tire is caused by vibrationat approximately 10 Hz to 100 Hz at near 50° C., for measuring theviscoelasticity of the tire, the magnitude of the rolling resistance canbe expressed by tan δ at 30° C. to 50° C.

A tire formed by using a resin material composed only of a thermoplasticelastomer has a tendency that when the number of hard segment regions ofthe thermoplastic elastomer is increased to increase the elasticmodulus, the loss tangent (tan δ) increases. Specifically, when theratio of the hard segment and the soft segment of the thermoplasticelastomer is changed to increase the elastic modulus, the peak of tan δof the thermoplastic elastomer in the measurement of viscoelasticitytends to be shifted to the higher temperature side, and the tan δ valueat 30° C. to 50° C. tends to increase. If the loss tangent (tan δ) of aresin material increases, the energy loss (heat generation) occurringupon deformation at the time of tire rolling tends to increase, and therolling resistance tends to increase. Accordingly, a car using a tire inwhich such a resin material is used as a raw material tends to have highfuel consumption.

That is, in a tire formed using a resin material that is composed onlyof a thermoplastic elastomer, if the elastic modulus of the resinmaterial is increased for the purpose of enhancing the resistance todeformation of the tire, the tan δ value of the resin material alsoincreases at the same time. Therefore, it has been difficult to realizea decrease of the rolling resistance.

On the other hand, when a tire frame is produced by using a resinmaterial of the constitution described above, and a tire is formedthereof, the resin material has a desired elastic modulus, and the tan δvalue can be suppressed to a low level. As a result, it is thought thatin the eighth aspect of the present invention, a suitable elasticmodulus is obtained, and also, a decrease in the rolling resistance ofthe tire can be realized.

(8-2) The tire of the eighth aspect of the present invention can beconfigured such that the resin (specific resin according to the eighthaspect of the present invention) is an acid-modified resin.

As such, when the resin material includes a thermoplastic elastomer andthe specific resin according to the eighth aspect of the presentinvention that has been acid-modified, the resin material has asea-island structure including a sea phase formed of a thermoplasticelastomer and an island phase formed of an acid-modified resin, or astructure in which the specific resin according to the eighth aspect ofthe present invention is dispersed in a thermoplastic elastomer. Whenthe interaction of the phase interface between the sea phase and theisland phase or the phase interface between the thermoplastic elastomerand the specific resin according to the eighth aspect of the presentinvention is weak, fluidity of the resin material increases, andexcellent injection molding properties are obtained. Since anacid-modified resin has an acid-modified site in the molecule, theinteraction with the thermoplastic elastomer is strong as compared witha resin that is not acid-modified.

On the other hand, in regard to the sea-island structure, there is atendency that as the acid value of the resin that is acid-modified ishigher, the island phase is smaller, and as the acid value is lower, theisland phase is larger.

(8-3) The tire of the eighth aspect of the present invention can beconfigured such that in regard to the configuration of (8-2), theacid-modified resin is an acid-modified polyolefin resin (for example,an acid-modified polypropylene, an acid-modified polyethylene, anacid-modified ethylene-propylene copolymer, or an ethylene-vinyl acetatecopolymer).

As such, when the particular resin according to the eighth aspect of thepresent invention is as described above, the tensile characteristicssuch as tensile elasticity and breaking strength as the tire performancecan be enhanced.

(8-4) The tire of the eighth aspect of the present invention can beconfigured such that in regard to the configuration of (8-2) or (8-3),the resin material further includes a resin that is other than thethermoplastic elastomer and is not acid-modified.

As such, when the resin material includes a thermoplastic elastomer, thespecific resin according to the eighth aspect of the present inventionthat is acid-modified, and a resin that is not acid-modified, the acidvalue can be adjusted, the tensile characteristics such as tensileelasticity and breaking strength can be enhanced while fluidity issuppressed, and excellent injection molding properties are obtained.

(8-5) The tire of the eighth aspect of the present invention can beconfigured such that in regard to the configuration of (8-4), the resinthat is not acid-modified is at least one selected from polyolefinresins (for example, polypropylene, polyethylene, and anethylene-propylene copolymer).

As such, when the resin that is not acid-modified is such as describedabove, the resin that is not acid-modified is compatible with theacid-modified resin, and injection molding at the time of tireproduction can be enhanced.

Furthermore, the resin that is not acid-modified is preferably a resinof the same kind as the acid-modified resin that is used together withthe resin that is not acid-modified. The “same kind” as used hereinmeans that two resins have a skeleton in which the skeleton thatconstitutes the main chain of the resin is common. A resin of the samekind for an acid-modified polypropylene corresponds to, for example,polypropylene, and a resin of the same kind for an acid-modifiedpolyethylene corresponds to, for example, polyethylene.

(8-6) The tire of the eighth aspect of the present invention can beconfigured such that the resin (specific resin according to the eighthaspect of the present invention) is a resin that is not acid-modified.

(8-7) The tire of the eighth aspect of the present invention can beconfigured such that in regard to the configuration of (8-6), the resinthat is not acid-modified is at least one selected from polyolefinresins (for example, polypropylene, polyethylene, and anethylene-propylene copolymer).

(8-8) The tire of the eighth aspect of the present invention can beconfigured such that the thermoplastic elastomer is at least oneselected from a polyamide-based thermoplastic elastomer, apolyester-based thermoplastic elastomer, a polystyrene-basedthermoplastic elastomer, or a polyurethane-based thermoplasticelastomer.

The polyamide-based thermoplastic elastomer, polyester-basedthermoplastic elastomer, polystyrene-based thermoplastic elastomer, andpolyurethane-based thermoplastic elastomer are advantageous in that theelastomers have heat resistance, and also exhibit excellent tensilemodulus of elasticity, tensile strength, and fracture strain.Furthermore, when a resin material including at least one selected fromthe polyamide-based thermoplastic elastomer, polyester-basedthermoplastic elastomer, polyurethane-based thermoplastic elastomer orpolystyrene-based thermoplastic elastomer is used in the tire frame, thestructure of the tire can be simplified as compared with conventionalrubber tires, and as a result, weight reduction of the tire can berealized. Therefore, when the tire frame is formed, a car using a tirethat employs such a resin material as the raw material exhibits improvedfuel efficiency.

The means for solving the problem of the ninth aspect is as follows.

(9-1) The tire of the ninth aspect of the present invention is a tireincluding at least a circular tire frame formed of a resin material, inwhich the resin material includes at least a first thermoplasticelastomer, a resin which is other than the first thermoplastic elastomerand has a glass transition temperature of 20° C. or lower, and a secondthermoplastic elastomer which is other than the first thermoplasticelastomer and which includes a hard segment of the same kind as theresin.

Here, the “thermoplastic elastomer” has the same definition as that usedin the third aspect of the present invention described above.

Furthermore, “thermoplastic elastomer including a hard segment of thesame kind as the resin” refers to a thermoplastic elastomer including ahard segment which has a skeleton that is common with the skeletonconstituting the main chain of the resin. The “resin” in the presentinvention according to the ninth aspect has the same definition as thatused in the first aspect of the present invention described above.However, the thermoplastic elastomer used in the ninth aspect of thepresent invention encompasses conventional vulcanized rubbers such asnatural rubber or synthetic rubbers.

Hereinafter, a resin that is other than a thermoplastic elastomer andhas a glass transition temperature of 20° C. or lower will be simplyreferred to as a “specific resin according to the ninth aspect of thepresent invention”.

It is thought that since the second thermoplastic elastomer includes ahard segment having a skeleton that is common with the skeletonconstituting the main chain of the specific resin according to the ninthaspect of the present invention, the affinity between the specific resinaccording to the ninth aspect of the present invention and the hardsegment of the second thermoplastic elastomer increases. Therefore, itis thought that compatibility between the specific resin according tothe ninth aspect of the present invention of the configuration describedabove and the second thermoplastic elastomer may be obtained, and thesetwo components are uniformly dispersed in the resin material.

Furthermore, it is thought that as the resin material further includes asecond thermoplastic elastomer in addition to the first thermoplasticelastomer and the specific resin according to the ninth aspect of thepresent invention, the thermoplastic resin material is imparted withflexibility, and as a result, impact resistance is improved.

Also, a tire formed using a resin material that is composed only of thefirst thermoplastic elastomer has a tendency that since the energy losscaused by a hysteresis loss occurring as a result of tire deformationincreases as the elastic modulus of the relevant resin materialincreases, a large rolling resistance is obtained, and the energy loss(heat generation) also increases. The rolling resistance of the tire canbe estimated from the loss tangent (tan δ) of the material constitutingthe tire, and for example, as the rolling resistance of the tire islarger, the tan δ value of the material that constitutes the tire tendsto increase.

That is, regarding a tire formed by using a resin material composed ofthe first thermoplastic elastomer alone, when the elastic modulus of theresin material is increased for the purpose of enhancing impactresistance and the like of the tire is increased, the tan δ value of theresin material also increases. Therefore, it has been difficult torealize the decrease of rolling resistance.

On the contrary, when a tire frame is produced by using a thermoplasticresin material having the constitution described above, and thus a tireis formed, the resin material has a desired elastic modulus, and the tanδ value can be suppressed to a low level. As a result, it is thoughtthat in the ninth aspect of the present invention, a suitable elasticmodulus is obtained, and also, a decrease in the rolling resistance ofthe tire can be realized.

(9-2) The tire of the ninth aspect of the present invention can beconfigured such that the resin (specific resin according to the ninthaspect of the present invention) is an acid-modified resin.

As such, when the resin material includes the first thermoplasticelastomer and the specific resin according to the ninth aspect of thepresent invention that is acid-modified, the resin material has asea-island structure including a sea phase formed of a thermoplasticelastomer and an island phase formed of an acid-modified resin, or astructure in which the specific resin according to the ninth aspect ofthe present invention is dispersed in a thermoplastic elastomer. Whenthe interaction of the phase interface between the sea phase and theisland phase or the phase interface between the thermoplastic elastomerand the specific resin according to the ninth aspect of the presentinvention is weak, fluidity of the resin material increases, andexcellent injection molding properties are obtained. Since anacid-modified resin has an acid-modified site in the molecule, theinteraction with the thermoplastic elastomer is strong as compared witha resin that is not acid-modified.

On the other hand, in regard to the sea-island structure, there is atendency that as the acid value of the resin that is acid-modified ishigher, the island phase is smaller, and as the acid value is lower, theisland phase is larger.

(9-3) The tire of the ninth aspect of the present invention can beconfigured such that in regard to the configuration of (9-2), theacid-modified resin is at least one selected from acid-modifiedpolyolefin resins (for example, an acid-modified polypropylene, anacid-modified polyethylene, an acid-modified ethylene-propylenecopolymer, and an ethylene-vinyl acetate copolymer).

As such, when the acid-modified resin is such as described above, thetensile characteristics such as tensile elasticity and breaking strengthas the tire performance can be enhanced.

(9-4) The tire of the ninth aspect of the present invention can beconfigured such that in regard to the configuration of (9-3), the secondthermoplastic elastomer is an olefin-based thermoplastic elastomer.

As such, it is thought that when the olefin-based thermoplasticelastomer as the second thermoplastic elastomer has a hard segmenthaving a skeleton that is common with the skeleton constituting the mainchain of the acid-modified polyolefin as the specific resin according tothe ninth aspect of the present invention, the affinity between theacid-modified polyolefin and the hard segment of the olefin-basedthermoplastic elastomer increases, compatibility between the twocomponents is obtained, and these two components are uniformly dispersedin the resin material.

Furthermore, it is thought that when the resin material further includesan olefin-based thermoplastic elastomer as the second thermoplasticelastomer in addition to the first thermoplastic elastomer and thespecific resin according to the ninth aspect of the present invention,the thermoplastic resin material is imparted with flexibility, and as aresult, impact resistance is enhanced.

(9-5) The tire of the ninth aspect of the present invention can beconfigured such that in regard to the configurations of (9-2) to (9-4),the resin material further includes a resin that is other than the firstthermoplastic elastomer and the second thermoplastic elastomer and isnot acid-modified.

As such, when the resin material includes the first thermoplasticelastomer, the specific resin according to the ninth aspect of thepresent invention that is acid-modified, the second thermoplasticelastomer, and a resin that is not acid-modified, the tensilecharacteristics such as tensile elasticity and breaking strength as thetire performance can be enhanced.

(9-6) The tire of the ninth aspect of the present invention can beconfigured such that in regard to the configuration of (9-5), the resinthat is not acid-modified is at least one selected from olefin resins(for example, polypropylene, polyethylene, and an ethylene-propylenecopolymer).

As such, when the resin that is not acid-modified is such as describedabove, the tensile characteristics such as tensile elasticity andbreaking strength as the tire performance can be further enhanced.

Furthermore, the resin that is not acid-modified is preferably a resinof the same kind as the acid-modified resin that is used in combination.The “same kind” as used herein means that the skeleton constituting themain chain of the two resins have a skeleton in common with each other.For example, with respect to an acid-modified polypropylene,polypropylene is a same kind thereof, and, with respect to anacid-modified polyethylene, polyethylene is a same kind thereof.

(9-7) The tire of the ninth aspect of the present invention can beconfigured such that in regard to the configuration of (9-6), theacid-modified resin is an acid-modified polyolefin, the resin that isnot acid-modified is polypropylene, and the second thermoplasticelastomer is an olefin-based thermoplastic elastomer containingpolypropylene.

As such, it is thought that when the olefin-based thermoplasticelastomer containing polypropylene as the second thermoplastic elastomerhas a hard segment having a skeleton that is common with the skeletonconstituting the main chain of the acid-modified polyolefin as thespecific resin according to the ninth aspect of the present inventionand is common with the skeleton constituting the main chain ofpolypropylene as the resin that is not acid-modified, the affinity ofthe acid-modified polyolefin, polypropylene, and the hard segment of theolefin-based thermoplastic elastomer containing polypropylene increases,and compatibility of these is obtained so that the polymers are moreuniformly dispersed in the resin material.

(9-8) The tire of the ninth aspect of the present invention can beconfigured such that the first thermoplastic elastomer is at least oneselected from a polyamide-based thermoplastic elastomer, apolyester-based thermoplastic elastomer, a polyurethane-basedthermoplastic elastomer, and a polystyrene-based thermoplasticelastomer.

The polyamide-based thermoplastic elastomer, polyester-basedthermoplastic elastomer, polyurethane-based thermoplastic elastomer andpolystyrene-based thermoplastic elastomer are advantageous in that theelastomers have heat resistance, and also exhibit excellent tensilemodulus of elasticity, tensile strength and fracture strain.Furthermore, when a resin material including at least one selected froma polyamide-based thermoplastic elastomer, a polyester-basedthermoplastic elastomer, a polyurethane-based thermoplastic elastomerand a polystyrene-based thermoplastic elastomer is used in the tireframe, the structure of the tire can be simplified as compared withconventional rubber tires, and as a result, weight reduction of the tirecan be realized. Therefore, when a tire frame is formed using the resinmaterial, a car using a tire in which such a resin material is used asthe raw material exhibits improved fuel efficiency.

The means for solving the problem of the tenth aspect is as follows.

(10-1) The tire of the tenth aspect of the present invention is a tireincluding at least a circular tire frame formed of a thermoplastic resinmaterial, in which the tire includes a reinforcing cord member thatforms a reinforcing cord layer on the outer circumference of the tireframe, and the thermoplastic resin material including at least apolyamide-based thermoplastic elastomer and a polyester-basedthermoplastic elastomer.

The reinforcing cord layer may be wound around the outer circumferenceof the tire frame in the circumferential direction, or may be woundaround the outer circumference in a crossing manner.

The tire of the tenth aspect of the present invention includes acircular tire frame formed of a thermoplastic resin material including apolyamide-based thermoplastic elastomer and a polyester-basedthermoplastic elastomer. Here, the “polyimide-based thermoplasticelastomer” has the same definition as that used in the first aspect ofthe present invention as described above.

The “polyester-based thermoplastic elastomer” has the same definition asthat used in the second aspect of the present invention described above.

The thermoplastic resin according to the tenth aspect of the presentinvention means a resin having thermoplasticity, and does not encompassconventional vulcanized rubbers such as natural rubber or syntheticrubbers.

The thermoplastic resin material including a polyamide-basedthermoplastic elastomer and a polyester-based thermoplastic elastomerhas excellent durability. More specifically, the resin material has heatresistance, and also exhibits excellent tensile modulus of elasticity,tensile strength and fracture strain. Therefore, when a tire frame isformed using the resin material, the tire obtains excellent durabilityand manufacturability. Furthermore, since the structure can besimplified, weight reduction can be expected.

Furthermore, since the thermoplastic resin material including apolyamide-based thermoplastic elastomer and a polyester-basedthermoplastic elastomer exhibits less temperature dependency of tensileyield strength, the resin material exhibits less deformation or changein hardness that is caused by temperature fluctuation in the useenvironment, and has a high deflection temperature under load.Therefore, the influence of the use temperature environment for the tirecan be decreased, and the tire can be used in an environment of a widerange of temperatures.

On the other hand, when the polyamide-based thermoplastic elastomer isused alone, in the case of adjusting the elastic modulus, it isnecessary to control the ratio of the hard segment and the soft segment.In this regard, when a polyamide-based thermoplastic elastomer and apolyester thermoplastic elastomer are used in combination, the elasticmodulus of the thermoplastic resin composition can be easily adjusted byadjusting the content ratio of the two components, as compared with thecase of using a polyamide-based thermoplastic elastomer alone.Therefore, the elastic modulus of the thermoplastic resin material canbe easily set to a desired range.

In an embodiment of the tire of the tenth aspect of the presentinvention, a reinforcing cord member is wound around the outercircumference of a tire frame formed of a thermoplastic resin materialincluding a polyamide-based thermoplastic elastomer and apolyester-based thermoplastic elastomer, and thus a reinforcing cordlayer is formed. When a reinforcing cord layer is formed on the outercircumference of the tire frame, the resistance to puncture andresistance to cutting of the tire, and the rigidity in thecircumferential direction of the tire (tire frame) are enhanced. Inaddition, when the rigidity in the circumferential direction isincreased, creeping (a phenomenon in which plastic deformation of thetire frame increases with time under a constant stress) in the tireframe formed of a thermoplastic material is suppressed.

Furthermore, a polyamide-based thermoplastic elastomer has highadhesiveness to the reinforcing cord members, and also exhibitsexcellent fixing performance such as welding strength. Therefore, when athermoplastic resin material including a polyamide-based thermoplasticelastomer and a polyester-based thermoplastic elastomer is used, forexample, the phenomenon in which air remains in the surroundings of thereinforcing cord members in the reinforcing cord winding step(incorporation of air) can be suppressed. If the thermoplastic resinmaterial has high adhesiveness and welding properties to the reinforcingcord, and incorporation of air into the surroundings of the reinforcingcord members is suppressed, the movement of the reinforcing cord memberdue to, for example, a force applied during driving can be effectivelysuppressed. Thereby, for example, even in the case where a tirecomponent member is disposed so as to cover the entirety of thereinforcing cord member in the outer circumference of the tire frame,since the movement of the reinforcing cord member is suppressed,detachment or the like between these members (including the tire frame)is prevented from occurring, and durability of the tire is enhanced.

(10-2) The tire of the tenth aspect of the present invention can beconfigured such that the reinforcing cord layer contains a resinmaterial. As such, when the reinforcing cord layer contains a resinmaterial, the difference in hardness between the tire and thereinforcing cord layer can be decreased as compared with the case offixing the reinforcing cord member with a cushion rubber, thereinforcing cord members can be further adhered and fixed to the tireframe. Thereby, the incorporation of air described above can beeffectively prevented, and the movement of the reinforcing cord memberat the time of driving can be effectively suppressed. Here, the “resinmaterial” is a concept including thermoplastic resins (includingthermoplastic elastomers) and thermosetting resins, and does notencompass vulcanized rubbers.

When the reinforcing cord layer contains a resin material, from theviewpoint of increasing the pull-out properties (difficulty to be pulledout) of the reinforcing cord member, the reinforcing cord member ispreferably covered by a resin material over 20% or more of the surfacethereof, and more preferably 50% or more of the surface thereof. Also,the content of the resin material in the reinforcing cord layer ispreferably 20 mass % or more, and more preferably 50 mass % or more,relative to the total amount of the materials that constitute thereinforcing cord layer excluding the reinforcing cord, from theviewpoint of increasing the pull-out properties of the reinforcingcords.

In order to configure the reinforcing cord layer to include a resinmaterial, for example, the reinforcing cord layer can be formed in aconfiguration such that when viewed from a cross-section of the tireframe along the axial direction, at least a portion of the reinforcingcord member is embedded in the outer circumference of the tire framethat is formed of a thermoplastic resin material. In this case, thethermoplastic resin material including a polyamide-based thermoplasticelastomer and a polyester-based thermoplastic elastomer of the outercircumference of the tire frame in which the reinforcing cord member isembedded corresponds to the resin material as a component of thereinforcing cord layer, and the polyamide-based thermoplastic elastomerforming the tire frame and the reinforcing cord member constitute thereinforcing cord layer. Furthermore, in order to configure thereinforcing cord layer to include a resin material, a coated cord memberobtained by coating a reinforcing cord with a resin material of the samekind as or different from the resin material that forms the tire frame,may be wound in the circumferential direction of the tire frame. The“same kind” as used for resin material means a situation in which bothare ester-based resin materials, or both are styrene-based resinmaterials, or the like.

(10-3) The tire of the tenth aspect of the present invention can beconfigured such that the mass ratio (x:y) of the polyamide-basedthermoplastic elastomer (x) and the polyester-based thermoplasticelastomer (y) in the thermoplastic resin is 95:5 to 50:50. As such, whenthe mass ratio (x:y) of the polyamide-based thermoplastic elastomer (x)and the polyester-based thermoplastic elastomer (y) is set to 95:5 to50:50, durability of the tire is further enhanced, and a tire which isnot easily deformed by temperature change can be obtained.

(10-4) The tire of the tenth aspect of the present invention can beconfigured such that the total content of the polyamide-basedthermoplastic elastomer and the polyester-based thermoplastic elastomerin the thermoplastic resin material is 50 mass % to 100 mass %. Byemploying the configuration described above, the performance that can beexhibited by a combination of a polyamide-based thermoplastic elastomerand a polyester-based thermoplastic elastomer can be further enhanced.

The tire of the tenth aspect of the present invention can be produced bya production method which includes a tire frame piece forming step offorming a tire frame piece for constituting a portion of a circular tireframe using a thermoplastic resin material including at least apolyamide-based thermoplastic elastomer and a polyester-basedthermoplastic elastomer; a tire frame piece bonding step of forming thetire frame by fusing two or more of the tire frame pieces that make apair, by applying heat to the bonding surface of the tire frame piece;and a reinforcing cord member winding step of winding a reinforcing cordmember around the outer circumference of the tire frame in thecircumferential direction, and forming a reinforcing cord layer.

In the production method described above, a tire frame piece of acircular tire frame can be formed using a thermoplastic resin materialincluding a polyamide-based thermoplastic elastomer and apolyester-based thermoplastic elastomer. The polyamide-basedthermoplastic elastomer included in the thermoplastic resin material canhave the melting point set to about 100° C. to 250° C., and thepolyester-based thermoplastic elastomer can have the melting point setto about 100° C. to 260° C. Therefore, for example, it is not necessaryto carry out the tire frame piece bonding step at or above 300° C., andthe bonding step can be carried out at a relatively low temperature.

Therefore, deterioration of the resin can be prevented, and deformationof the tire frame piece can be suppressed. Accordingly, the productyield can be increased, and productivity of the tire can be increased.

Furthermore, tire frame pieces that a thermoplastic resin materialincluding a polyamide-based thermoplastic elastomer are bonded to form atire frame, the adhesive strength between the tire frame pieces issufficient, and the performance of the frame itself is not deterioratedby the temperature at the time of bonding. Therefore, durability at thetime of driving such as the resistance to puncture or heat resistance ofthe tire thus produced can be enhanced.

The means for solving the problem of the eleventh aspect is as follows.

(11-1) The tire of the eleventh aspect of the present invention is atire including at least a circular tire frame formed of a thermoplasticresin material, in which the thermoplastic resin material includes apolyamide-based thermoplastic elastomer, and at least one copolymerselected from an olefin-(meth)acrylate copolymer or a metal crosslinkedproduct (ionomer) of an olefin-(meth)acrylic acid copolymer.

Here, the “thermoplastic elastomer” has the same definition as that usedin the first aspect of the present invention described above.

Also, the “polyamide-based thermoplastic elastomer” has the samedefinition as that used in the first aspect of the present inventiondescribed above.

The resin in the eleventh aspect of the present invention means a resinhaving a thermoplastic resin (including thermoplastic elastomers) or athermosetting resin, and does not encompass conventional vulcanizedrubbers such as natural rubber or synthetic rubbers. The thermoplasticelastomer also does not encompass conventional vulcanized rubbers suchas natural rubber or synthetic rubbers.

The “at least one copolymer selected from an olefin-(meth)acrylatecopolymer or a metal crosslinked product of an olefin-(meth)acrylic acidcopolymer” is also referred to as a specific copolymer.

Meanwhile, “(meth)acrylic acid” means at least one of acrylic acid ormethacrylic acid, and “(meth)acrylate” means at least one of acrylate ormethacrylate.

When the thermoplastic resin material according to the eleventh aspectof the present invention includes a specific copolymer and a polyamidethermoplastic elastomer, the thermoplastic resin material has excellentimpact resistance. Furthermore, since the thermoplastic resin materialof the eleventh aspect of the present invention that includes apolyamide-based thermoplastic elastomer and a specific copolymer hasless temperature dependency of the tensile yield strength, thedeformation or change in hardness due to temperature fluctuation of theuse environment is suppressed. Therefore, when a tire is formed by usinga thermoplastic resin material of the eleventh aspect of the presentinvention, the influence of the use temperature environment on the tirecan be reduced, and the tire can be used in an environment of a widerange of temperature.

In the case of using a polyamide-based thermoplastic elastomer alone,when an attempt is made to adjust the elastic modulus, it is necessaryto control the ratio of the hard segment and the soft segment. In thisregard, when a polyamide-based thermoplastic elastomer and a specificcopolymer are used in combination, the elastic modulus of thethermoplastic resin material can be easily adjusted by adjusting thecontent ratio of the two components, compared to the case of using apolyamide-based thermoplastic elastomer alone.

Furthermore, in order to cause the thermoplastic resin material to haveyield strength, it can be considered to use a polyamide-basedthermoplastic elastomer and an olefin-based resin such as polyethylenein mixture (blend). However, since the olefin-based resin (for example,polyethylene) does not have a polar group, even if the olefin-basedresin is blended with the polyamide-based thermoplastic elastomer, theaffinity is poor. Thus, by copolymerizing a polyolefin with a monomerhaving a polar group, and thus introducing a polar group into themolecule, the polyolefin-based resin can be made to have affinity with apolyamide-based thermoplastic elastomer. As such, when a polyolefin iscopolymerized with acrylic acid or methacrylic acid as a monomer havinga polar group, the affinity of the copolymer thus obtained and apolyamide-based thermoplastic elastomer is improved, but there have beencases in which the yield strength of the thermoplastic resin materialincluding the copolymer and the polyamide-based thermoplastic elastomerdepends on temperature.

In this regard, when a monomer obtained by esterifying or metal-ionizingacrylic acid or methacrylic acid is used instead of acrylic acid ormethacrylic acid, and a copolymer of the monomer obtained by esterifyingor metal-ionizing acrylic acid or methacrylic acid with polyethylene isused as a copolymer that is used in combination with a polyamide-basedthermoplastic elastomer, the impact resistance of the thermoplasticresin material including the copolymer and the polyamide-basedthermoplastic elastomer can be increased, and temperature dependency ofthe yield strength can be suppressed.

(11-2) The tire of the eleventh aspect of the present invention can beconfigured such that the mass ratio (x:y) of the polyamide-basedthermoplastic elastomer (x) and the specific copolymer (y) is 95:5 to50:50.

When the content of the polyamide-based thermoplastic elastomer in thethermoplastic resin material is in the range described above, theperformance of the thermoplastic resin material can be sufficientlyexhibited, and the tensile characteristics such as tensile elasticityand breaking strength as the tire performance can be enhanced.

(11-3) The tire of the eleventh aspect of the present invention can beconfigured such that the total content of the polyamide-basedthermoplastic elastomer and the specific copolymer in the thermoplasticresin material is 50 mass % to 100 mass %.

When the total content of the polyamide-based thermoplastic elastomerand the specific copolymer in the thermoplastic resin material is in therange described above, the performance of the thermoplastic resinmaterial can be sufficiently exhibited, and the tensile characteristicssuch as tensile elasticity and breaking strength as the tire performancecan be further enhanced.

(11-4) It can be configured such that the olefin-(meth)acrylatecopolymer is an ethylene-(meth)acrylate copolymer.

When the olefin-(meth)acrylate copolymer is an ethylene-(meth)acrylatecopolymer, flexibility of the thermoplastic resin material can befurther enhanced, and impact resistance as the tire performance can befurther enhanced.

(11-5) It can be configured such that the metal crosslinked product ofthe olefin-(meth)acrylic acid copolymer is a metal crosslinked productof an ethylene-(meth)acrylic acid copolymer.

When the metal crosslinked product of the olefin-(meth)acrylic acidcopolymer is a metal crosslinked product of an ethylene-(meth)acrylicacid copolymer, flexibility of the thermoplastic resin material can befurther enhanced, and impact resistance as the tire performance can befurther enhanced.

Furthermore, the tire of the eleventh aspect of the present inventionmay include a reinforcing cord member that is wound around the outercircumference of a tire frame formed of a thermoplastic resin materialto form a reinforcing cord member layer, in addition to a tire frameformed of a thermoplastic resin material.

When the reinforcing cord member is wound around the outer circumferenceof the tire frame formed of a thermoplastic resin material to form areinforcing cord member layer, the resistance to puncture and resistanceto cutting of the tire and the rigidity in the circumferential directionof the tire (tire frame) are enhanced. Furthermore, when the rigidity inthe circumferential direction is enhanced, creeping (a phenomenon inwhich plastic deformation of the tire frame increases with time under aconstant stress) in the tire frame formed of a thermoplastic material issuppressed.

The means for solving the problem of the twelfth aspect is as follows.

(12-1) The tire of the twelfth aspect of the present invention is a tireincluding at least a circular tire frame formed of a thermoplastic resinmaterial, in which the thermoplastic resin material includes apolyamide-based thermoplastic elastomer, an olefin-(meth)acrylic acidcopolymer, and an acid-modified copolymer formed by acid-modifying anolefin-(meth)acrylate copolymer.

Here, the “thermoplastic elastomer” has the same definition as that usedin the first aspect of the present invention described above.

Furthermore, the “polyimide-based thermoplastic elastomer” has the samedefinition as that used in the first aspect of the present inventiondescribed above.

In addition, the resin according to the twelfth aspect of the presentinvention means a thermoplastic or thermosetting resin, and does notencompass conventional vulcanized rubbers such as natural rubber orsynthetic rubbers. The thermoplastic elastomer also does not encompassconventional vulcanized rubbers such as natural rubber or syntheticrubbers.

Furthermore, the “olefin-(meth)acrylic acid copolymer” refers to acopolymer containing a (meth)acrylic acid-derived partial structure inthe olefin repeating unit. “(Meth)acrylic acid” means at least one ofacrylic acid or methacrylic acid.

The “acid-modified copolymer formed by acid-modifying anolefin-(meth)acrylate copolymer” refers to a copolymer obtained bybonding a compound having an acidic group to a copolymer containing a(meth)acrylate-derived partial structure in an olefin repeating unit.“(Meth)acrylate” means at least one of acrylate and methacrylate.

The “olefin-(meth)acrylic acid copolymer” is referred to as a specificcopolymer, and the “acid-modified copolymer obtained by acid-modifyingan olefin-(meth)acrylate copolymer” is also referred to as a specificacid-modified copolymer.

Here, the olefin that constitutes an olefin repeating unit in thespecific copolymer and the specific acid-modified copolymer ispreferably ethylene, propylene, or 1-butene, and ethylene is morepreferred.

Since the thermoplastic resin material in the twelfth aspect of thepresent invention includes the specific copolymer, the specificacid-modified copolymer, and a polyamide-based thermoplastic elastomer,the thermoplastic resin material exhibits excellent injection moldingproperties, impact resistance and fracture properties.

In the case of using a polyamide-based thermoplastic elastomer alone,when an attempt is made to adjust the elastic modulus, it is necessaryto control the ratio of the hard segment and the soft segment.Furthermore, when the thermoplastic resin material includes apolyamide-based thermoplastic elastomer and the specific copolymer, theresin material tends to break in a lamellar form when stretched. In thisregard, when at least three components of a polyamide-basedthermoplastic elastomer, the specific copolymer and the specificacid-modified copolymer are used in combination, the elastic modulus ofthe thermoplastic resin material can be easily adjusted by adjusting thecontent ratio of the three components, and the state of fracture whenstretched can be improved, as compared with the case of using apolyamide-based thermoplastic elastomer alone.

(12-2) The tire of the twelfth aspect of the present invention can beconfigured such that the mass ratio (x:y+z) of the polyamide-basedthermoplastic elastomer (x), the olefin-(meth)acrylic acid copolymer(specific copolymer; y) and the acid-modified copolymer (specificacid-modified copolymer; z) is 95:5 to 50:50.

When the mass ratio of the polyamide-based thermoplastic elastomer, theolefin-(meth)acrylic acid copolymer and the acid-modified copolymer inthe thermoplastic resin material is in the range described above, theperformance of the thermoplastic resin material can be sufficientlyexhibited, and the tensile characteristics such as tensile elasticityand breaking strength as the tire performance can be enhanced.

In addition, the tire of the twelfth aspect of the present invention canbe configured such that the mass ratio (y:z) of the olefin-(meth)acrylicacid copolymer (specific copolymer; y) and the acid-modified copolymer(specific acid-modified copolymer; z) is 95:5 to 20:80.

When the mass ratio of the specific copolymer and the specificacid-modified copolymer in the thermoplastic resin material is in therange described above, the performance of the thermoplastic resinmaterial can be sufficiently exhibited, and the tensile characteristicssuch as tensile elasticity and breaking strength as the tire performancecan be enhanced.

(12-3) The tire of the twelfth aspect of the present invention can beconfigured such that the total content of the polyamide-basedthermoplastic elastomer, the olefin-(meth)acrylic acid copolymer(specific copolymer) and the acid-modified copolymer (specificacid-modified copolymer) in the thermoplastic resin material is 50 mass% to 100 mass %.

When the total content of the polyamide-based thermoplastic elastomer,the specific copolymer, and the specific acid-modified copolymer in thethermoplastic elastomer is in the range described above, the performanceof the thermoplastic resin material can be sufficiently exhibited, andthe tensile characteristics such as tensile elasticity and breakingstrength as the tire performance can be further enhanced.

Furthermore, the tire of the twelfth aspect of the present invention mayinclude a reinforcing cord member that is wound around the outercircumference of a tire frame formed of a thermoplastic resin materialto form a reinforcing cord layer, in addition to the tire frame formedof a thermoplastic resin material.

When the reinforcing cord member is wound around the outer circumferenceof a tire frame formed of a thermoplastic resin material to form areinforcing cord member layer, the resistance to puncture and resistanceto cutting of the tire, and the rigidity in the circumferentialdirection of the tire (tire frame) are enhanced. In addition, when therigidity in the circumferential direction is enhanced, creeping (aphenomenon in which plastic deformation of the tire frame increases withtime under a constant stress) in the tire frame formed of athermoplastic material is suppressed.

(12-4) The tire of the twelfth aspect of the present invention can beconfigured such that the olefin-(meth)acrylic acid copolymer is anethylene-(meth)acrylic acid copolymer, and the acid-modified copolymeris an acid-modified copolymer obtained by acid-modifying anethylene-(meth)acrylate copolymer.

When the configuration described above is employed, the performance ofthe thermoplastic resin material can be sufficiently exhibited, and thetensile characteristics such as tensile elasticity and breaking strengthas the tire performance can be enhanced.

(12-5) The method for producing a tire of the twelfth aspect of thepresent invention includes at least a tire frame piece forming step offorming a tire frame piece for constituting a portion of a circular tireframe using a thermoplastic resin material including a polyamide-basedthermoplastic elastomer, an olefin-(meth)acrylic acid copolymer, and anacid-modified copolymer obtained by acid-modifying anolefin-(meth)acrylate copolymer; and a tire frame piece bonding step offorming a tire frame by fusing two or more of the tire frame pieces,which make a pair, by applying heat to the bonding surface of the tireframe piece.

In the method for producing a tire of the twelfth aspect of the presentinvention, a tire frame piece of the circular tire frame is formed usinga thermoplastic resin material. Since the thermoplastic resin materialaccording to the twelfth aspect of the present invention includes thepolyamide-based thermoplastic elastomer, the specific copolymer, and thespecific acid-modified copolymer, the resin material exhibits excellentfluidity. Therefore, injection molding using the thermoplastic resinmaterial can be easily carried out. Therefore, productivity of the tirecan be enhanced.

This is thought to be because of the following.

Due to the acid group carried by the specific acid-modified copolymer,the miscibility between the polyamide-based thermoplastic elastomer andthe specific copolymer is increased, so that when the polyamide-basedthermoplastic elastomer is formed into a sea phase, and the specificcopolymer is formed into an island phase, the sea-island structure canbe easily formed. It is thought that in such a sea-island structure, thespecific acid-modified copolymer is present in the interface between theisland phase and the sea phase and thus increases the affinity betweenthe sea phase and the island phase. When the affinity between the seaphase and the island phase increases, the thermoplastic resin materialhas increased viscosity; however, when the thermoplastic resin materialincludes the specific copolymer, the affinity can be adjusted, andexcellent fluidity is obtained. Therefore, it is thought that injectionmolding can be easily carried out.

(12-6) The method for producing a tire of the twelfth aspect of thepresent invention can be configured such that the olefin-(meth)acrylicacid copolymer is an ethylene-(meth)acrylic acid copolymer, and theacid-modified copolymer is an acid-modified copolymer obtained byacid-modifying an ethylene-(meth)acrylate copolymer.

When the configuration described above is employed, the performance ofthe thermoplastic resin material can be sufficiently exhibited, and atire having excellent tensile characteristics such as tensile elasticityand breaking strength as the tire performance can be produced.

The means for solving the problem of the thirteenth aspect is asfollows.

(13-1) The tire of the thirteenth aspect of the present invention is atire including at least a circular tire frame formed of a thermoplasticresin material, in which the tire includes a reinforcing cord memberthat forms a reinforcing cord layer on the outer circumference of thetire frame, and the thermoplastic resin material includes at least apolyamide-based thermoplastic elastomer and a rubber.

The reinforcing cord layer may be wound around the outer circumferenceof the tire frame in the circumferential direction, or may be woundaround the outer circumference in a crossing manner.

The tire of the thirteenth aspect of the present invention includes acircular tire frame formed of a thermoplastic resin material including apolyamide-based thermoplastic elastomer and a rubber.

Here, the “thermoplastic elastomer” has the same definition as that usedin the first aspect of the present invention described above.

The “polyimide-based thermoplastic elastomer” has the same definition asthat used in the first aspect of the present invention described above.

A “rubber” is a polymer compound having elasticity, but in thethirteenth aspect of the present invention, the rubber is distinguishedfrom the thermoplastic elastomer described above.

In the thermoplastic elastomer, a hard segment which is crystalline andhas a high melting point behaves as a pseudo-crosslinking point, andelasticity is exhibited. On the other hand, the rubber has, for example,double bonds in the molecular chain, and produces a three-dimensionalnetwork structure when crosslinked by added sulfur or the like(vulcanized), thereby exhibiting elasticity. Therefore, when athermoplastic elastomer is heated, the hard segment melts, and when athermoplastic elastomer is cooled, the hard segment reproducespseudo-crosslinking points again. Thus, recycling is enabled. On theother hand, a rubber produces a three-dimensional structure whencrosslinked (vulcanized) and loses fluidity, so that recycling isdifficult even if heated. However, a rubber that is not crosslinkedbehaves like a thermoplastic elastomer.

The thermoplastic resin in the thirteenth aspect of the presentinvention a means a resin having thermoplasticity, and does notencompass conventional vulcanized rubbers such as natural rubber orsynthetic rubbers. However, the “thermoplastic resin material” in thethirteenth aspect of the present invention means a material including atleast a thermoplastic resin, and encompasses a material including arubber in addition to a thermoplastic resin.

The thermoplastic resin material according to the thirteenth aspect ofthe invention is flexible and has excellent impact resistance. Thethermoplastic resin material is also excellent in tensilecharacteristics such as tensile modulus of elasticity and tensilestrength. Therefore, when a tire frame is formed of the thermoplasticresin material, the durability and manufacturability of the tire becomeexcellent. Furthermore, since the structure can be simplified, there isan advantage that weight reduction can be expected.

On the other hand, in the case of using a polyamide-based thermoplasticelastomer alone, when an attempt is made to adjust the elastic modulus,it is necessary to control the ratio of the hard segment and the softsegment. In this regard, when a polyamide-based thermoplastic elastomerand a rubber are used in combination, the elastic modulus of thethermoplastic resin material can be easily adjusted by adjusting thecontent ratio of the two components, compared to the case of using apolyamide-based thermoplastic elastomer alone.

Since the rolling resistance of a tire is caused by vibration atapproximately 10 Hz to 100 Hz at near 50° C., for measuring theviscoelasticity of the tire, the magnitude of the rolling resistance canbe expressed by tan δ at 30° C. to 50° C. When the tan δ value at 30° C.to 50° C. is small, the rolling resistance of the tire also tends tobecome small.

Here, in the case of using a polyamide-based thermoplastic elastomeralone, when the dynamic viscoelasticity is measured, a peak of tan δoriginating from the polyamide-based thermoplastic elastomer can beseen, and as the elastic modulus of the polyamide-based thermoplasticelastomer increases, the peak value tends to shift to the highertemperature side. For example, when the dynamic viscoelasticity ofUBESTA XPA9055X1 manufactured by Ube Industries, Ltd. is measured, apeak is detected at near 10° C.

On the other hand, when the dynamic viscoelasticity of a rubber ismeasured, a peak is generally detected at −10° C. or lower. Therefore,when a polyamide-based thermoplastic elastomer and a rubber are mixed,the peak height originating from the polyamide-based thermoplasticelastomer is decreased depending on the mixing proportions, and the peakheight originating from the rubber increases. However, since the peakposition of the rubber is −10° C. or lower, the influence on the tan δvalue at 30° C. to 50° C. is reduced, and therefore, the tan δ value isdecreased as a whole.

In an embodiment of the tire of the thirteenth aspect of the presentinvention, a reinforcing cord member is wound around the outercircumference of the tire frame formed of a thermoplastic resin materialincluding a polyamide-based thermoplastic elastomer and a rubber, toform a reinforcing cord layer. When a reinforcing cord layer is formedaround the outer circumference of the tire frame, the resistance topuncture and resistance to cutting of the tire, and the rigidity in thecircumferential direction of the tire (tire frame) are enhanced.Meanwhile, when the rigidity in the circumferential direction isincreased, creeping (a phenomenon in which plastic deformation of thetire frame increases with time under a constant stress) in the tireframe formed of a thermoplastic material is suppressed.

Furthermore, a polyamide-based thermoplastic elastomer can easilypenetrate not only between the fibers of the reinforcing cord memberitself, but also between twisted cords in the case where the reinforcingcord member has a twisted-fiber structure, due to the low melt viscosityof the elastomer. Accordingly, the polyamide-based thermoplasticelastomer has high adhesiveness to reinforcing cord member, and hasexcellent fixing performance such as welding strength. Also, when thereinforcing cord member is an organic fiber, since the polyamide-basedthermoplastic elastomer that forms the tire frame can be welded to thereinforcing cord member, high welding properties and excellent fixingperformance are obtained. Further, since a polyamide-based thermoplasticelastomer exhibits excellent elongation, the fracture properties areexcellent. Therefore, when a thermoplastic resin material including apolyamide-based thermoplastic elastomer and another elastomer is used,for example, the phenomenon in which air remains in the surroundings ofthe reinforcing cord members in the reinforcing cord winding step(incorporation of air) can be suppressed. If the polyamide-basedthermoplastic elastomer has high adhesiveness and welding properties tothe reinforcing cords, and incorporation of air into the surroundings ofthe reinforcing cord members is suppressed, the movement of thereinforcing cord member due to, for example, a force applied duringdriving can be effectively suppressed. Thereby, for example, even in thecase where a tire-constituting member is provided so as to cover theentirety of the reinforcing cord member in the outer circumference ofthe tire frame, since the movement of the reinforcing cord member issuppressed, detachment or the like between these members (including thetire frame) is prevented from occurring, and durability of the tire isenhanced.

(13-2) The thermoplastic resin material may further include athermoplastic elastomer that has good affinity with the rubber.Particularly, when the thermoplastic resin material includes an acidmodification product as the thermoplastic elastomer having good affinitywith the rubber, the rubber can be finely dispersed in the thermoplasticresin material. Furthermore, it is speculated that the tensile strengthis enhanced by the interaction between the polyamide-based thermoplasticelastomer and the acid-modified sites, and even if fractured, the resinmaterial undergoes ductile fracture, so that brittle fracture orlamellar fracture does not easily occur.

The phrase “having good affinity with rubber” implies that when athermoplastic elastomer is mixed with a rubber, the molecular skeletonof the rubber and the molecular skeleton of the thermoplastic elastomerare similar, and the rubber is in a state of being incorporated into thedispersed particles of the thermoplastic elastomer, or the thermoplasticelastomer is in a state of being incorporated into the dispersedparticles of the rubber.

However, not all of the thermoplastic elastomer and the rubber in thethermoplastic resin material need to be in the state described above,and the thermoplastic elastomer and the rubber in the thermoplasticresin material may be partially in the state described above.

(13-3) The tire of the thirteenth aspect of the present invention can beconfigured such that the reinforcing cord layer contains a resinmaterial. As such, when a resin material is contained in the reinforcingcord layer, the difference in hardness between the tire and thereinforcing cord layer can be decreased as compared to the case offixing the reinforcing cord member with a cushion rubber, and therefore,the reinforcing cord member can be adhered and fixed to the tire framefurther. Thereby, the incorporation of air can be effectively prevented,and the movement of the reinforcing cord at the time of driving can beeffectively suppressed. Here, the “resin material” in the thirteenthaspect of the present invention is a material including at least aresin, and this material may also include not only a resin, but also arubber or an inorganic compound. Meanwhile, the “resin” is a conceptwhich encompasses a thermoplastic resin (including a thermoplasticelastomer) and a thermosetting resin, and does not encompass a rubber(including a vulcanized rubber) or an inorganic compound.

When the reinforcing cord layer contains a resin material, from theviewpoint of increasing the pull-out properties (difficulty to be pulledout) of the reinforcing cord, the reinforcing cord is preferably coveredby a resin material over 20% or more of the surface, and more preferably50% or more of the surface. Also, the content of the resin material inthe reinforcing cord layer is preferably 20 mass % or more, and morepreferably 50 mass % or more, relative to the total amount of thematerials that constitute the reinforcing cord layer excluding thereinforcing cords, from the viewpoint of increasing the pull-outproperties of the reinforcing cords.

In order to configure the reinforcing cord layer to include a resinmaterial, for example, the reinforcing cord layer can be formed in aconfiguration such that when viewed from a cross-section of the tireframe along the axial direction, at least a portion of the reinforcingcord member is embedded in the outer circumference of the tire framethat is formed of a thermoplastic resin material. In this case, thethermoplastic resin material including a polyamide-based thermoplasticelastomer and a rubber of the outer circumference of the tire frame inwhich the reinforcing cord member is embedded corresponds to the resinmaterial that constitutes the reinforcing cord layer, and thethermoplastic resin material forming the tire frame and the reinforcingcord member constitute the reinforcing cord layer. Furthermore, in orderto configure the reinforcing cord layer to include a resin material, acoated cord member obtained by coating a reinforcing cord with a resinmaterial of the same kind as or different from the resin material thatforms the tire frame, may be wound in the circumferential direction ofthe tire frame. The “same kind” as used for resin material means asituation in which both are ester-based resin materials, or both arestyrene-based resin materials, or the like.

(13-4) The tire of the thirteenth aspect of the present invention can beconfigured such that the mass ratio (x:y) of the polyamide-basedthermoplastic elastomer (x) and the rubber (y) in the thermoplasticresin material is 95:5 to 50:50. As such, when the mass ratio (x:y) ofthe polyamide-based thermoplastic elastomer (x) and the rubber (y) isadjusted to 95:5 to 50:50, the performance that can be exhibited by thecombination of the polyamide-based thermoplastic elastomer and therubber can be further enhanced.

However, when the thermoplastic resin material includes a thermoplasticelastomer other than a polyamide-based thermoplastic elastomer, the tirecan be configured such that the mass ratio (x:y′) between the total (y′)of the rubber and the thermoplastic elastomer other than thepolyamide-based thermoplastic elastomer and of the polyamide-basedthermoplastic elastomer (x) is 95:5 to 50:50.

(13-5) The tire of the thirteenth aspect of the present invention can beconfigured such that the mass ratio (x:y+z) of the polyamide-basedthermoplastic elastomer (x), the rubber (y) and the thermoplasticelastomer having good affinity with the rubber (z) in the thermoplasticresin material is 95:5 to 50:50. As such, when the mass ratio (x:y+z) ofthe polyamide-based thermoplastic elastomer (x), the rubber (y) and thethermoplastic elastomer other than the polyamide-based thermoplasticelastomer (z) is adjusted to 95:5 to 50:50, the performance that can beexhibited by the combination of the polyamide-based thermoplasticelastomer and the rubber can be further enhanced.

(13-6) The tire of the thirteenth aspect of the present invention can beconfigured such that the total content of the polyamide-basedthermoplastic elastomer and the rubber in the thermoplastic resinmaterial is 50 mass % to 100 mass %. When the configuration describedabove is employed, the performance that can be exhibited by thecombination of the polyamide-based thermoplastic elastomer and therubber can be further enhanced.

However, when the thermoplastic resin material includes a thermoplasticelastomer other than the polyamide-based thermoplastic elastomer, thetire can be configured such that the total amount of the polyamide-basedthermoplastic elastomer, the rubber, and the thermoplastic elastomerother than the polyamide-based thermoplastic elastomer is 50 mass % to100 mass %.

(13-7) The tire of the thirteenth aspect of the present invention can beconfigured such that the total content of the polyamide-basedthermoplastic elastomer, the rubber, and the thermoplastic elastomerhaving good affinity with the rubber in the thermoplastic resin materialis 50 mass % to 100 mass %. When the configuration described above isemployed, the performance that can be exhibited by the combination ofthe polyamide-based thermoplastic elastomer and the rubber can befurther enhanced.

When the configuration described above is employed, the performance thatcan be exhibited by the combination of the polyamide-based thermoplasticelastomer and the rubber can be further enhanced.

Effects of the Invention

According to the first aspect of the present invention, a tire in whichair is prevented from remaining in a region around the reinforcing cord,and which has high durability at the time of driving and exhibitsexcellent productivity, can be provided.

According to the second aspect of the present invention, a tire in whichair is prevented from remaining in a region around the reinforcing cord,and which has high durability at the time of driving and exhibitsexcellent manufacturability and impact resistance, can be provided.

According to the third aspect of the present invention, a tire which isformed using a thermoplastic resin material and has excellent tensileelasticity and fracture properties, and a method for producing this tirecan be provided.

According to the fourth aspect of the present invention, a tire which isformed using a thermoplastic resin material and exhibits excellentsteering stability with small rolling resistance can be provided.

According to the fifth aspect the present invention, a tire which ishighly elastic, has a low loss factor, and exhibits excellent heatresistance can be provided.

According to the sixth aspect of the present invention, a tire which isformed using a thermoplastic resin material and has excellent antistaticperformance can be provided.

According to the seventh aspect of the present invention, a tire whichis formed using a thermoplastic resin material, and in which even if theelastic modulus is increased, an increase in rolling resistance can besuppressed, can be provided.

According to the eighth aspect of the present invention, a tire which isformed using a resin material, and in which an elastic modulus in apreferable range is obtained and an increase in rolling resistance canbe suppressed, can be provided.

According to the ninth aspect of the present invention, a tire which isformed using a resin material and can have enhanced impact resistance,can be provided.

According to the tenth aspect of the present invention, a tire which hashigh durability at the time of driving since air is prevented fromremaining in a region around the reinforcing cord member, and which isnot easily affected by temperature change, can be provided.

According to the eleventh aspect of the present invention, a tire whichis formed using a thermoplastic resin material and has excellent impactresistance, and in which the temperature dependency of the tensile yieldstrength is suppressed, can be provided.

According to the twelfth aspect of the present invention, a tire whichis formed using a thermoplastic resin material and has excellent impactresistance and fracture properties, and a method for producing a tirewith excellent productivity, can be provided.

According to the thirteenth aspect of the present invention, a tirewhich has excellent impact resistance since air is prevented fromremaining in a region around the reinforcing cord, can be provided.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a perspective view illustrating a partial cross-section of atire according to an embodiment of the present invention.

FIG. 1B is a cross-sectional view illustrating a bead portion fittedonto a rim in the embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along a tire rotation axis, whichillustrates a state where a reinforcing cord is embedded in a crownportion of a tire case of the tire according to the embodiment of thepresent invention.

FIG. 3 is a diagram illustrating an operation of embedding thereinforcing cord in the crown portion of the tire case by the use of acord heating apparatus and rollers.

FIG. 4 is a cross-sectional view of a tire according to anotherembodiment of the present invention.

FIG. 5A is a perspective view illustrating a partial cross-section of atire according to the embodiment of the present invention.

FIG. 5B is a cross-sectional view illustrating a bead portion fitted toa rim in the embodiment of the present invention.

FIG. 6 is a cross-sectional view taken along a tire width direction,which illustrates the region around a reinforcing layer, of the tireaccording to the embodiment of the present invention.

FIG. 7 relates to the third aspect of the present invention, and is aSEM photograph of a sample piece according Example 3-1 made of athermoplastic resin.

FIG. 8 relates to the third aspect of the present invention, and is aSEM photograph of a sample piece according Example 3-8 made of athermoplastic resin material.

FIG. 9 relates to the third aspect of the present invention, and is aSEM photograph of a sample piece according Comparative Example 3-3 madeof a thermoplastic resin material in the third aspect of the presentinvention.

FIG. 10 relates to the fifth aspect of the present invention, andillustrates a relationship between the glass transition temperature andthe loss factor (tan δ) in each material.

FIG. 11 relates to the seventh aspect of the present invention, and is agraph in which a relationship between a tensile modulus of elasticityand tan δ in each sample piece according to examples and comparativeexamples made of a thermoplastic resin material is plotted.

FIG. 12 relates to the seventh aspect of the present invention, and is agraph in which a relationship between a tensile modulus of elasticityand tan δ in each sample piece according to the examples and thecomparative examples made of a thermoplastic resin material is plotted.

FIG. 13 relates to the tenth aspect of the present invention, and is agraph in which a relationship between a tensile yield strength and atemperature in each sample piece used in the examples and thecomparative examples is plotted.

FIG. 14 relates to the tenth aspect of the present invention, and is agraph in which a relationship between a tensile yield strength and atemperature in each sample piece used in the examples and thecomparative examples is plotted.

BEST MODE FOR CARRYING OUT THE INVENTION

<<Invention According to First Aspect>>

First, a thermoplastic resin material containing a polyamide-basedthermoplastic elastomer and forming a tire frame and a resin materialforming a reinforcing cord layer in the present invention according to afirst aspect will be described, and specific embodiments of a tire ofthe first aspect of the invention will then be described with referenceto the drawings.

[Thermoplastic Resin Including Polyamide-Based Thermoplastic Elastomer]

The tire of the first aspect of the invention has a tire frame formedfrom a thermoplastic resin material that includes at least apolyamide-based thermoplastic elastomer.

Here, the “polyamide-based thermoplastic elastomer” means athermoplastic resin material made from a copolymer having a polymerconstituting a hard segment that is crystalline and has a high meltingpoint and a polymer constituting a soft segment that is non-crystallineand has a low glass transition temperature, the thermoplastic resinmaterial having an amide bond (—CONH—) in the main chain of the polymerconstituting the hard segment. Examples of the polyamide-basedthermoplastic elastomer include amide-based thermoplastic elastomers(TPA), etc. as specified in JIS K6418:2007, and polyamide-basedelastomers, etc. described in JP-A No. 2004-346273.

The polyamide-based thermoplastic elastomer may be a material in whichat least a polyamide constitutes a crystalline hard segment having ahigh melting point and another polymer (for example, a polyester or apolyether) constitutes a non-crystalline soft material having a lowglass transition temperature. Further, in the polyamide-basedthermoplastic elastomer, a chain extending agent such as a dicarboxylicacid may be used in addition to the hard segment and the soft segment.Examples of the polyamide for forming the hard segment include apolyamide produced using a monomer represented by the following generalformula (1) or (2).

H₂N—R¹—COOH  General Formula (1)

In General Formula (1), R¹ represents a hydrocarbon molecular chainhaving 2 to 20 carbon atoms or an alkylene group having 2 to 20 carbonatoms.

In General Formula (2), R² represents a hydrocarbon molecular chainhaving 3 to 20 carbon atoms or an alkylene group having 3 to 20 carbonatoms.

In General Formula (1), R¹ is preferably a hydrocarbon molecular chainhaving 3 to 18 carbon atoms or an alkylene group having 3 to 18 carbonatoms, more preferably a hydrocarbon molecular chain having 4 to 15carbon atoms or an alkylene group having 4 to 15 carbon atoms, andparticularly preferably a hydrocarbon molecular chain having 10 to 15carbon atoms or an alkylene group having 10 to 15 carbon atoms. Further,in General Formula (2), R² is preferably a hydrocarbon molecular chainhaving 3 to 18 carbon atoms or an alkylene group having 3 to 18 carbonatoms, more preferably a hydrocarbon molecular chain having 4 to 15carbon atoms or an alkylene group having 4 to 15 carbon atoms, andparticularly preferably a hydrocarbon molecular chain having 10 to 15carbon atoms or an alkylene group having 10 to 15 carbon atoms.

Examples of the monomer represented by General Formula (1) or (2)include an w-aminocarboxylic acid and a lactam. Further, examples of thepolyamide that forms the hard segment include a polycondensate of aω-aminocarboxylic acid or a lactam, and a copolycondensate of a diamineand a dicarboxylic acid.

Examples of the ω-aminocarboxylic acid include aliphaticω-aminocarboxylic acids having 5 to 20 carbon atoms, such as6-aminocaproic acid, 7-aminoheptanoic acid, 8-aminooctanoic acid,10-aminocapric acid, 11-aminoundecanoic acid, and 12-aminododecanoicacid. Further, examples of the lactam include aliphatic lactams having 5to 20 carbon atoms, such as lauryllactam, ε-caprolactam, undecalactam,ω-enantholactam, and 2-pyrrolidone.

Examples of the diamine include diamine compounds, for example,aliphatic diamines having 2 to 20 carbon atoms, such as ethylenediamine,trimethylenediamine, tetramethylenediamine, hexamethylenediamine,heptamethylenediamine, octamethylenediamine, nonamethylenediamine,decamethylenediamine, undecamethylenediamine, dodecamethylenediamine,2,2,4-trimethylhexamethylenediamine,2,4,4-trimethylhexamethylenediamine, 3-methylpentamethylenediamine, andmethaxylenediamine. Further, the dicarboxylic acid may be represented byHOOC—(R³)m-COOH (R³: a hydrocarbon molecular chain having 3 to 20 carbonatoms, m: 0 or 1), and examples thereof include aliphatic dicarboxylicacids having 2 to 20 carbon atoms, such as oxalic acid, succinic acid,glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid,sebacic acid, and dodecanedioic acid.

A polyamide obtained by ring-opening polycondensation of lauryllactam,ε-caprolactam, or udecanelactam can preferably be used as the polyamidethat forms the hard segment.

The polymer that forms the soft segment may be, for example, a polyesteror a polyether, and examples thereof include polyethylene glycol,polypropylene glycol, polytetramethylene ether glycol, and an ABA-typetriblock polyether. These may be used singly or in combination of two ormore kinds thereof. A polyether diamine obtained by allowing terminalsof a polyether with ammonia or the like, for example, may also be used.

Here, the “ABA-type triblock polyether” means a polyether represented bythe following General Formula (3).

In General Formula (3), x and z each independently represent an integerof 1 to 20. y represents an integer of 4 to 50.

In General Formula (3), x and z are each preferably an integer of 1 to18, more preferably an integer of 1 to 16, particularly preferably aninteger of 1 to 14, and most preferably an integer of 1 to 12. Further,in General Formula (3), y is each preferably an integer of 5 to 45, morepreferably an integer of 6 to 40, particularly preferably an integer of7 to 35, and most preferably an integer of 8 to 30.

Examples of the combination of the hard segment and the soft segmentinclude any combination of any of the hard segments described above andany of the soft segments described above. Among these, a combination ofa ring-opening polycondensate of lauryllactam with polyethylene glycol,a combination of a ring-opening polycondensate of lauryllactam withpolypropylene glycol, a combination of a ring-opening polycondensate oflauryllactam with polytetramethylene ether glycol, and a combination ofa ring-opening polycondensate of lauryllactam with an ABA-type triblockpolyether are preferable, and a combination of a ring-openingpolycondensate of lauryllactam with an ABA-type triblock polyether isparticularly preferable.

The number average molecular weight of the polymer constituting the hardsegment (polyamide) is preferably from 300 to 15,000, from the viewpointof melt moldability. Further, the number average molecular weight of thepolymer constituting the soft segment is preferably from 200 to 6,000,from the viewpoints of toughness and low-temperature flexibility.Further, the mass ratio (x:y) of the hard segment (x) to the softsegment (y) is preferably from 50:50 to 90:10, and more preferably from50:50 to 80:20, from the viewpoint of melt moldability.

The polyamide-based thermoplastic elastomer can be synthesized bycopolymerizing a polymer that forms the hard segment and a polymer thatforms the soft segment, using known methods.

Commercially available products such as UBESTA XPA series (for example,XPA9063X1, XPA9055X1, XPA9048X2, XPA9048X1, XPA9040X1, and XPA9040X2)from Ube Industries, Ltd. and VESTAMID series (for example, E40-S3,E47-S1, E47-S3, E55-S1, E55-S3, EX9200, and E50-R2) from Daicel-EvonikLtd. can be used as the polyamide-based thermoplastic elastomer.

The melting point of the thermoplastic resin material containing apolyamide-based thermoplastic elastomer is, approximately, usually 100°C. to 350° C., and preferably 100° C. to 250° C. From the viewpoint ofthe productivity of tires, the melting point is preferably approximatelyfrom 120° C. to 250° C., and more preferably from 130° C. to 200° C. Forexample, in a case in which a frame of a tire is formed by fusion ofdivided bodies (frame pieces) thereof, the heating temperature for thebonding section can be set to be equal to or higher than the meltingpoint of the thermoplastic resin material that forms the tire frame, byusing a thermoplastic resin material containing a polyamide-basedthermoplastic elastomer having a melting point of 120 to 250° C. asdescribed above. Since a thermoplastic resin material containing apolyamide-based thermoplastic elastomer is used in the tire of the firstaspect of the invention, the bonding strength between the tire framepieces is sufficient even in the case of a frame fused in thetemperature range of 120° C. to 250° C. Therefore, the tire of the firstaspect of the invention has excellent durability at the time of driving,such as puncture resistance and abrasion resistance. Further, theheating temperature is preferably a temperature that is 10° C. to 150°C. higher, and more preferably 10° C. to 100° C. higher, than themelting point of the thermoplastic resin material containing apolyamide-based thermoplastic elastomer for forming the tire framepieces.

Furthermore, in the first aspect of the invention, the content ratio ofthe polyamide-based thermoplastic elastomer in the thermoplastic resinmaterial is not particularly limited, and is preferably 50 to 100% bymass or more, and more preferably 90 to 100% by mass, with respect tothe total amount of the thermoplastic resin material. When the contentratio of the polyamide-based thermoplastic elastomer is 50% by mass to100% by mass with respect to the total amount of the thermoplastic resinmaterial, the characteristics of the polyamide-based thermoplasticelastomer can sufficiently be exerted, and the durability orproductivity of the tire can be improved. The thermoplastic resinmaterial may contain, if desired, rubber, other thermoplasticelastomers, thermoplastic resins, various fillers (for example, silica,calcium carbonate, and clay), and various additives such as anti-agingagents, oils, plasticizers, colorants, weather resistant agents, andreinforcing agents.

In the first aspect of the invention, the thermoplastic resin materialcontaining a polyamide-based thermoplastic elastomer has a tensilemodulus of elasticity (hereinafter, “elastic modulus” in thisspecification means a tensile modulus of elasticity unless specificallyindicated otherwise) as defined in JIS K7113:1995 of preferably 100 MPato 1000 MPa, more preferably 100 MPa to 800 MPa, and still morepreferably 100 MPa to 700 MPa. When the tensile modulus of elasticity ofthe thermoplastic resin material is 100 to 1000 MPa, fitting onto a rimcan be carried out efficiently while maintaining the shape of the frameof the tire.

In the first aspect of the invention, the thermoplastic resin materialcontaining a polyamide-based thermoplastic elastomer preferably has atensile yield strength as defined in JIS K7113:1995 of equal to orhigher than 5 MPa, more preferably 5 MPa to 20 MPa, and still morepreferably 5 MPa to 17 MPa. When the tensile yield strength of thethermoplastic resin material is equal to or higher than 5 MPa,resistance to deformation caused by a load applied to a tire duringtraveling or the like can be achieved.

In the first aspect of the invention, the thermoplastic resin materialcontaining a polyamide-based thermoplastic elastomer preferably has atensile yield elongation as defined in JIS K7113:1995 of equal to orhigher than 10%, more preferably 10% to 70%, and still more preferably15% to 60%. When the tensile yield elongation of the thermoplastic resinmaterial is equal to or higher than 10%, the elastic region is large,and the fittability onto a rim is improved.

In the first aspect of the invention, the thermoplastic resin materialcontaining a polyamide-based thermoplastic elastomer preferably has atensile elongation at break as defined in JIS K7113:1995 of equal to orhigher than 50%, more preferably equal to or higher than 100%, stillmore preferably equal to or higher than 150%, and particularlypreferably equal to or higher than 200%. When the tensile elongation atbreak of the thermoplastic resin material is equal to or higher than50%, fittability onto a rim is excellent, and resistance to breaking atcollision can be obtained.

In the first aspect of the invention, the thermoplastic resin materialcontaining a polyamide-based thermoplastic elastomer preferably has adeflection temperature under load (under a load of 0.45 MPa) as definedin ISO 75-2 or ASTM D648 of equal to or higher than 50° C., morepreferably 50° C. to 150° C., and still more preferably 50° C. to 130°C. When the deflection temperature under load of the thermoplastic resinmaterial is equal to or higher than 50° C., deformation of a tire framecan be suppressed even in cases in which vulcanization is performedduring the production of a tire.

[Resin Material as Component of Reinforcing Cord Layer]

The tire according to the first aspect of the invention may beconfigured to include a resin material in the reinforcing cord layer.When a resin material is included in the reinforcing cord layer asdescribed above, a difference in hardness between the tire and thereinforcing cord layer can be decreased, and, therefore, the reinforcingcord member can be more tightly adhered and fixed to the tire frame,compared with a case in which the reinforcing cord member is fixed usinga cushion rubber. The concept of a simple expression “resin”, such asthat described above, encompasses thermoplastic resins (includingthermoplastic elastomers) as well as thermosetting resins, but does notencompass vulcanized rubbers.

In a case in which the reinforcing cord member is a steel cord, and inwhich an attempt is made to separate the reinforcing cord member fromthe cushion rubber at the time of disposal of the tire, vulcanizedrubbers are difficult to separate from the reinforcing cord member onlyby heating; in contrast, resin materials can be separated from thereinforcing cord member only by heating, which is advantageous in termsof recyclability of the tire. Resin materials usually have a loss factor(tan δ) lower than that of vulcanized rubbers. Accordingly, when thereinforcing cord layer contains a large amount of resin material, therolling properties of the tire can be enhanced. Resin materials, havinga higher elastic modulus relative to vulcanized rubbers, areadvantageous in that the resin materials have high in-plane shearstiffness, and also provide excellent steering stability and excellentabrasion resistance at the time of traveling with the tire.

Examples of the thermosetting resin which may be used in the reinforcingcord layer include phenol resins, urea resins, melamine resins, epoxyresins, polyamide resins, polyester resins, etc.

Examples of the thermoplastic resin include urethane resins, olefinresins, vinyl chloride resins, polyamide resins, and polyester resins.

Examples of the thermoplastic elastomer include amide-basedthermoplastic elastomers (TPA), polyester-based thermoplastic elastomers(TPC), polyolefin-based thermoplastic elastomers (TPO),polystyrene-based thermoplastic elastomers (TPS), polyurethane-basedthermoplastic elastomers (TPU), thermoplastic cross-linked rubbers(TPV), and other thermoplastic elastomers (TPZ), which are defined inJIS K6418:2007. It is preferable to use a thermoplastic elastomer, inconsideration of elasticity necessary for traveling and moldability forproduction.

The “same kind” as used for resin material means a situation in whichboth are ester-based resin materials, or both are styrene-based resinmaterials, or the like.

The elastic modulus (the tensile modulus of elasticity defined in JISK7113:1995) of the resin material used in the reinforcing cord layer ispreferably set to be within a range of 0.1 times to 10 times the elasticmodulus of the thermoplastic resin that forms the tire frame. When theelastic modulus of the resin material is equal to or lower than 10 timesthe elastic modulus of the thermoplastic resin material that forms thetire frame, the crown portion is not excessively rigid, and thefittability onto a rim is facilitated. When the elastic modulus of theresin material is equal to or higher than 0.1 times the elastic modulusof the thermoplastic resin material that forms the tire frame, the resinas a component of the reinforcing cord layer is not excessively soft,the belt in-plane shear stiffness is excellent, and cornering force isimproved.

When a resin material is contained in the reinforcing cord layer, it ispreferable that 20% or more of the surface of the reinforcing cordmember is covered with the resin material, and it is more preferablethat 50% or more of the surface of the reinforcing cord member iscovered with the resin material, from the viewpoint of improving thedrawing properties (resistance to drawing) of the reinforcing cord. Fromthe viewpoint of improving the drawing properties of the reinforcingcord, the content of the resin material in the reinforcing cord layer ispreferably equal to or higher than 20 wt %, and more preferably equal toor higher than 50 wt %, with respect to the total content of thematerials, other than the reinforcing cord, that constitute thereinforcing cord layer.

Embodiment 1-1

A tire according to Embodiment 1-1 of the tire of the first aspect ofthe invention will be described below with reference to the drawings.

A tire 10 according to this embodiment will be described below. FIG. 1Ais a perspective view illustrating a cross-section of a part of a tireaccording to one embodiment of the invention. FIG. 1B is across-sectional view of a bead portion fitted to a rim. As shown in FIG.1, the tire 10 according to this embodiment has substantially the samecross-sectional shape as those of conventional general rubber pneumatictires.

As shown in FIG. 1A, the tire 10 includes a tire case 17 composed of: apair of bead portions 12 each contacting with a bead seat 21 and a rimflange 22 of a rim 20 shown in FIG. 1B; side portions 14 that extendfrom the bead portions 12 toward the outer side in the tire radialdirection; and a crown portion 16 (outer peripheral portion) thatconnect the outer end in the tire radial direction of one side portion14 and the outer end in the tire radial direction of the other sideportion 14.

The tire case 17 according to the present embodiment is formed of apolyamide-based thermoplastic elastomer (“UBESTA XPA9055X1” manufacturedby Ube Industries, Ltd., melting point: 162° C.). Although the tire case17 according to the present embodiment is formed of a singlethermoplastic resin material (a polyamide-based thermoplasticelastomer), the first aspect of the invention is not limited to thisconfiguration, and thermoplastic resin materials having differentcharacteristics may be used for the respective portions of the tire case17 (such as the side portions 14, the crown portion 16, and the beadportions 12), similarly to conventional general rubber pneumatic tires.A reinforcing material (such as fiber, cord, unwoven fabric, and wovenfabric which are formed of a polymer material or a metal) may bedisposed to be embedded in the tire case 17 (such as in the beadportions 12, in the side portions 14, or in the crown portion 16) so asto reinforce the tire case 17 with the reinforcing material.

The tire case 17 according to the present embodiment is formed bybonding a pair of tire case half parts (tire frame pieces) 17A formed ofa polyamide-based thermoplastic elastomer to each other. The tire casehalf parts 17A is formed by placing circular tire case half parts 17Athat have the same shape and that are obtained by molding one beadportion 12, one side portion 14, and a half-width of the crown portion16 as an integral body by injection molding or the like, to face eachother, and bonding the half parts to each other at the tire equatorialplane portion. The tire case 17 is not limited to that obtained bybonding two members, and may be formed by bonding three or more members.

Each tire case half part 17A formed of a polyamide-based thermoplasticelastomer can be molded by, for example, vacuum molding, pressuremolding, injection molding, or melt casting. Accordingly, when comparedwith a conventional case in which the tire case is molded from rubber,it is not necessary to perform vulcanization, as a result of which theproduction process can remarkably be simplified, and the molding timecan be saved.

In the present embodiment, the tire case half parts 17A have a symmetricshape, that is, one tire case half part 17A and the other tire case halfpart 17A have the same shape; therefore, there is an advantage in thatthe tire case half parts 17A can be molded using only one type of mold.

In the present embodiment, as shown in FIG. 1B, an annular bead core 18formed of a steel cord is embedded in each bead portion 12, similarly toconventional general pneumatic tire. However, the first aspect of theinvention is not limited to this configuration; the bead core 18 may beomitted as long as the rigidity of the bead portions 12 is ensured andthere is no problem in fitting to the rim 20. Other than the steel cord,the bead core may be formed of an organic fiber cord, a resin-coatedorganic fiber cord, a hard resin, or the like.

In the present embodiment, an annular sealing layer 24 formed of amaterial having higher sealing properties than those of thepolyamide-based thermoplastic elastomer constituting the tire case 17,for example rubber, is provided on a part of the bead portion 12 thatcontacts the rim 20 or at least on a part of the bead portion 12 thatcontacts the rim flange 22 of the rim 20. The sealing layer 24 may alsobe provided in a part in which the tire case 17 (the bead portion 12)and the bead seat 21 contact each other. A material softer than thepolyamide-based thermoplastic elastomer that constitutes the tire case17 may be used as the material having higher sealing properties thanthose of the polyamide-based thermoplastic elastomer that constitutesthe tire case 17. It is preferable to use, as a rubber usable for thesealing layer 24, the same kind of rubber as a rubber used on the outersurface of a bead portion of a conventional general rubber pneumatictire. When the sealing between the bead portion 12 and the rim 20 can beensured only with the polyamide-based thermoplastic elastomer, therubber sealing layer 24 may be omitted, or other thermoplastic resins(thermoplastic elastomers) having higher sealing properties than thoseof the polyamide-based thermoplastic elastomer may be used. Examples ofother thermoplastic resins include resins such as a polyurethane-basedresin, a polyolefin-based resin, a polystyrene-based resin, and apolyester resin, and a blend of any of these resins with a rubber or anelastomer. Thermoplastic elastomers can also be used, and examplesthereof include a polyester-based thermoplastic elastomer, apolyurethane-based thermoplastic elastomer, a polystyrene-basedthermoplastic elastomer, and a polyolefin-based thermoplastic elastomer,and any combination of these elastomers and a blend of any of theseelastomers with a rubber.

As shown in FIG. 1, in the crown portion 16, a reinforcing cord 26having higher rigidity than that of the polyamide-based thermoplasticelastomer constituting the tire case 17 is wound in the circumferentialdirection of the tire case 17. The reinforcing cord 26 is helicallywound to form a reinforcing cord layer 28 in a state in which at least apart of the reinforcing cord 26 is embedded in the crown portion 16 in across-sectional view taken along the axial direction of the tire case17. A tread 30 formed of a material, such as rubber, having higherabrasion resistance than that of the polyamide-based thermoplasticelastomer constituting the tire case 17 is disposed on the outercircumference side in the tire radial direction of the reinforcing cordlayer 28.

The reinforcing cord layer 28 formed by the reinforcing cord 26 will bedescribed below with reference to FIG. 2. FIG. 2 is a cross-sectionalview taken along the tire rotation axis, which illustrates a state inwhich the reinforcing cord is embedded in the crown portion of the tirecase of the tire according to Embodiment 1-1. As shown in FIG. 2, thereinforcing cord 26 is helically wound in a state in which at least apart of the reinforcing cord 26 is embedded in the crown portion 16 in across-sectional view taken along the axial direction of the tire case17, and, together with a part of the outer circumferential portion ofthe tire case 17, forms the reinforcing cord layer 28 specified by thedotted lines in FIG. 2. The part of the reinforcing cord 26 that isembedded in the crown portion 16 is in close contact with thepolyamide-based thermoplastic elastomer constituting the crown portion16 (the tire case 17). A monofilament (single filament) of a metalfiber, an organic fiber, or the like, or a multifilament (strandedfilament) in which fibers are stranded, such as a steel cord composed ofsteel fibers, may be used as the reinforcing cord 26. In the presentembodiment, a steel cord is used as the reinforcing cord 26.

The embedding depth L in FIG. 2 represents the depth of embedding of thereinforcing cord 26 in the tire case 17 (the crown portion 16) in thetire rotation axis direction. The depth of embedding L of thereinforcing cord 26 in the crown portion 16 is preferably equal to orgreater than ⅕ of the diameter D of the reinforcing cord 26, and morepreferably more than ½ of the diameter D of the reinforcing cord 26. Itis most preferable that the entire reinforcing cord 26 be embedded inthe crown portion 16. When the depth of embedding L of the reinforcingcord 26 is more than ½ of the diameter D of the reinforcing cord 26, thereinforcing cord 26 is difficult to drop off from the embedded portiondue to the dimensions of the reinforcing cord 26. When the reinforcingcord 26 is entirely embedded in the crown portion 16, the surface (theouter circumferential surface) becomes flat, whereby entry of air intoan area around the reinforcing cord can be suppressed even when a memberis placed on the crown portion 16 in which the reinforcing cord 26 isembedded. The reinforcing cord layer 28 corresponds to a belt disposedon the outer circumferential surface of a carcass of a conventionalrubber pneumatic tire.

As described above, the tread 30 is disposed on the outercircumferential side in the tire radial direction of the reinforcingcord layer 28. It is preferable that the same kind of rubber as thatused for conventional rubber pneumatic tires is used as the rubber usedfor the tread 30. It is also possible to use, instead of the tread 30, atread formed of another kind of thermoplastic resin material which hashigher abrasion resistance than that of the polyamide-basedthermoplastic elastomer constituting the tire case 17. In the tread 30,a tread pattern composed of plural grooves is formed on the contactsurface that comes into contact with a road surface, similarly toconventional rubber pneumatic tires.

A method of producing a tire of the first aspect of the invention willbe described below.

(Tire Case Forming Step)

First, tire case half parts supported by thin metal support rings arearranged to face each other. Subsequently, a mold for bonding, which isnot shown in the drawings, is placed so as to contact the outercircumferential surface of a portion at which the tire case half partsare contacted with each other. Here, the mold for bonding is configuredto pressurize a region at or around the bonding section (the contactportion) of the tire case half parts A with a predetermined pressure.Then, the region at or around the bonding section of the tire case halfparts is pressurized at a temperature equal to or higher than themelting point of the thermoplastic resin material that constitutes thetire case. When the bonding section of the tire case half parts isheated and pressurized by the mold for bonding, the bonding section ismelted, and the tire case half parts are fused with each other, as aresult of which the members are integrated to form the tire case 17.Although the bonding section of the tire case half parts is heated usingthe mold for bonding in the present embodiment, the invention accordingto the first aspect is not limited to this configuration; heating of thebonding section may be carried out using, for example, aseparately-provided high-frequency heater, or the tire case half partsmay be bonded by softening or melting the bonding section, in advance,via application of hot air, irradiation of infrared rays or the like,and pressurizing the bonding section using the mold for bonding.

(Reinforcing Cord Member Winding Step)

Next, a reinforcing cord winding step will be described below using FIG.3. FIG. 3 is an explanatory diagram explaining an operation of embeddingthe reinforcing cord in the crown portion of the tire case using a cordheating device and rollers. In FIG. 3, a cord feeding apparatus 56includes a reel 58 on which a reinforcing cord 26 is wound, a cordheating device 59 disposed at the downstream side in the cord feedingdirection of the reel 58, a first roller 60 disposed at the downstreamside in the reinforcing cord 26 feeding direction, a first cylinder unit62 for moving the first roller 60 in directions in which the firstroller comes into contact with and get away from the outercircumferential surface of the tire, a second roller 64 disposed at thedownstream side in the reinforcing cord 26 feeding direction of thefirst roller 60, and a second cylinder unit 66 for moving the secondroller 64 in directions in which the first roller comes into contactwith and get away from the outer circumferential surface of the tire.The second roller 64 can be used as a cooling roller formed of metal. Inthe present embodiment, the surface of the first roller 60 or the secondroller 64 is coated with a fluororesin (TEFLON (registered trademark) inthe case of the present embodiment) with a view to suppressing adhesionof the melted or softened polyamide-based thermoplastic elastomer.Although the cord feeding apparatus 56 is configured to have two rollersof the first roller 60 and the second roller 64 in the presentembodiment, the first aspect of the invention is not limited to thisconfiguration, and the cord feeding apparatus may be configured to haveonly one of these rollers (that is, a single roller).

The cord heating device 59 includes a heater 70 and a fan 72 thatgenerate hot air. The cord heating device 59 includes a heating box 74into which hot air is supplied and in which the reinforcing cord 26passes through the inside space thereof, and an discharge port 76through which the heated reinforcing cord 26 is discharged.

In this step, first, the temperature of the heater 70 of the cordheating device 59 is increased, and the air around the heater 70 heatedby the heater 70 is sent to the heating box 74 by an air currentgenerated by the rotation of the fan 72. Then, the reinforcing cord 26drawn out from the reel 58 is fed to the inside of the heating box 74 ofwhich the inner space is heated with hot air, whereby the reinforcingcord 25 is heated (for example, to increase the temperature of thereinforcing cord 26 to be about 100° C. to about 200° C.). The heatedreinforcing cord 26 passes through the discharge port 76, and ishelically wound, with a constant tension, around the outercircumferential surface of the crown portion 16 of the tire case 17rotating in the direction of arrow R in FIG. 3. Here, as a result of theheated reinforcing cord 26 coming into contact with the outercircumferential surface of the crown portion 16, the polyamide-basedthermoplastic elastomer at the contact portion is melted or softened,and at least a part of the heated reinforcing cord 26 is embedded in theouter circumferential surface of the crown portion 16. In this process,since the heated reinforcing cord 26 is embedded in the melted orsoftened polyamide-based thermoplastic elastomer, the polyamide-basedthermoplastic elastomer and the reinforcing cord 26 get into a state inwhich no space is left between the polyamide-based thermoplasticelastomer and the reinforcing cord 26, that is, in a tightly-contactedstate. Accordingly, the incorporation of air into the portion in whichthe reinforcing cord 26 is embedded is suppressed. By heating thereinforcing cord 26 to a temperature higher than the melting point ofthe polyamide-based thermoplastic elastomer of the tire case 17, themelting or softening of the polyamide-based thermoplastic elastomer inthe portion contacting the reinforcing cord 26 is promoted. By employingthis configuration, embedding of the reinforcing cord 26 in the outercircumferential surface of the crown portion 16 is facilitated, and theincorporation of air can effectively be suppressed.

The depth L of embedding of the reinforcing cord 26 can be adjusted bythe heating temperature for the reinforcing cord 26, the tension appliedto the reinforcing cord 26, the pressure applied from the first roller60, etc. In the present embodiment, the depth L of embedding of thereinforcing cord 26 is set to be equal to or greater than ⅕ of thediameter D of the reinforcing cord 26. The depth L of embedding of thereinforcing cord 26 is more preferably more than ½ of the diameter D,and it is still more preferable that the entire reinforcing cord 26 isembedded.

In this way, a reinforcing cord layer 28 is formed on the outercircumference side of the crown portion 16 of the tire case 17 bywinding the heated reinforcing cord 26 on the outer circumferentialsurface of the crown portion 16 such that the heated reinforcing cord 26is embedded in the outer circumferential surface of the crown portion16.

A belt-shaped vulcanized tread 30 is wound on the outer circumferentialsurface of the tire case 17 for one revolution, and the tread 30 isbonded to the outer circumferential surface of the tire case 17 using,for example, an adhesive. For example, precured treads known thus farfor use in retreaded tires may be used as the tread 30. This step is astep similar to a step of bonding a precured tread to the outercircumferential surface of a casing of a retreaded tire.

A tire 10 can be completed by bonding a sealing layer 24 formed of avulcanized rubber to the bead portion 12 of the tire case 17 using, forexample, an adhesive.

(Effects)

In the tire 10 according to the present embodiment, since the tire case17 is formed of a polyamide-based thermoplastic elastomer, the tire 10has excellent heat resistance, excellent tensile modulus of elasticity,excellent tensile strength, and excellent fracture strain. In addition,since the tire 10 has a structure simpler than those of conventionalrubber tires, the weight thereof is small. Therefore, the tire 10according to the present embodiment has excellent abrasion resistanceand durability. Further, since the polyamide-based thermoplasticelastomer constituting the tire case 17 has a melting point of 162° C.,bonding of the tire case half parts 17A can sufficiently be carried outat a temperature of, for example, 250° C. or lower; therefore, energyconsumption can be reduced, and the cost incurred for heating can bereduced.

The polyamide-based thermoplastic elastomer has high adhesiveness to thereinforcing cord 26, and has excellent fixing performance such aswelding strength. Therefore, a phenomenon (incorporation of air) inwhich air remains around the reinforcing cord 26 can be suppressed inthe reinforcing cord winding step. The high adhesiveness and weldabilityto the reinforcing cord 26 and suppression of incorporation of air intoa region around the reinforcing cord member effectively suppressmovement of the reinforcing cord 26 at the time a force is appliedduring traveling. Accordingly, for example, even in a case in whichtire-constituting members are disposed on the outer circumference of thetire frame so as to cover the entire reinforcing cord member, themovement of the reinforcing cord member is suppressed, wherebyseparation between the members (including the tire frame), for example,is suppressed, and the durability of the tire 10 is improved.

In the tire 10 according to the present embodiment, since thereinforcing cord 26 having higher rigidity than that of thepolyamide-based thermoplastic elastomer is helically wound on the outercircumferential surface of the crown portion 16 of the tire case 17formed of a thermoplastic resin material in the circumferentialdirection, puncture resistance, cutting resistance, and rigidity in thecircumferential direction of the tire 10 are improved. The improvedrigidity in the circumferential direction of the tire 10 preventscreeping of the tire case 17 formed of a thermoplastic resin material.

In a cross-sectional view taken along the axial direction of the tirecase 17 (the cross-section shown in FIG. 1), at least a part of thereinforcing cord 26 is embedded in the outer circumferential surface ofthe crown portion 16 of the tire case 17 formed of the polyamide-basedthermoplastic elastomer, and is in close contact with thepolyamide-based thermoplastic elastomer, as a result of whichincorporation of air during production is suppressed, and movement ofthe reinforcing cord 26 due to, for example, a force applied at the timeof traveling is suppressed. Accordingly, separation between thereinforcing cord 26, the tire case 17, and the tread 30 is suppressed,and the durability of the tire 10 is improved.

As shown in FIG. 2, since the depth L of embedding of the reinforcingcord 26 is set to be equal to or greater than ⅕ of the diameter Dthereof, incorporation of air during production is effectivelysuppressed, and movement of the reinforcing cord 26 due to a forceapplied at the time of traveling is further suppressed.

In a case in which the reinforcing cord layer 28 is configured toinclude the polyamide-based thermoplastic elastomer as described above,the reinforcing cord 26 can be made to more tightly contact the tirecase 17 and fixed to the tire case 17 since the difference in hardnessbetween the tire case 17 and the reinforcing cord layer 28 can be madesmaller than that in a case in which the reinforcing cord 26 is fixedusing a cushion rubber. Accordingly, the incorporation of air mentionedabove can effectively be prevented, and the movement of the reinforcingcord member at the time of traveling can effectively be suppressed.

In a case in which the reinforcing cord 26 is a steel cord, thereinforcing cord 26 can easily be separated from the polyamide-basedthermoplastic elastomer by heating and recovered at the time ofdisposing of the tire, and, therefore, there is an advantage from theviewpoint of recyclability of the tire 10. Further, since thepolyamide-based thermoplastic elastomer has a lower loss factor (tan δ)compared with vulcanized rubbers, inclusion of a large amount ofpolyamide-based thermoplastic elastomer in the reinforcing cord layer 28makes it possible to enhance the rolling properties of the tire.Compared with vulcanized rubbers, the polyamide-based thermoplasticelastomer has advantages in terms of high in-plane shear stiffness,excellent steering stability at the time of traveling with the tire, andexcellent abrasion resistance.

Since the tread 30 that contacts a road surface is formed of a rubbermaterial having higher abrasion resistance than that of thepolyamide-based thermoplastic elastomer, the abrasion resistance of thetire 10 is improved.

Since the annular bead core 18 formed of a metal material is embedded inthe bead portion 12, the tire case 17 is strongly fixed to the rim 20,i.e., the tire 10 is strongly fixed to the rim 20, similarly toconventional rubber pneumatic tires.

Since the sealing layer 24 formed of a rubber material having highersealing ability than the polyamide-based thermoplastic elastomer isdisposed in a region of the bead portion 12 that contacts the rim 20,sealing between the tire 10 and the rim 20 is improved. Therefore,compared with a case in which sealing is carried out with the rim 20 andthe polyamide-based thermoplastic elastomer, air leakage from the tireis further suppressed. Further, provision of the sealing layer 24 alsoimproves fittability to the rim.

Although a configuration in which the reinforcing cord 26 is heated suchthat the polyamide-based thermoplastic elastomer in a portion thatcontacts the heated reinforcing cord 26 is melted or softened is adoptedin the embodiment described above, the first aspect of the invention isnot limited to this configuration; a hot air generating device may beused, instead of heating the reinforcing cord 26, to heat the outercircumferential surface of the crown portion 16 in which the reinforcingcord 26 is to be embedded, and the reinforcing cord 26 may thereafter beembedded in the crown portion 16.

Although the heat source of the cord heating device 59 includes theheater and the fan in Embodiment 1-1, the first aspect of the inventionis not limited to this configuration, and a configuration in which thereinforcing cord 26 is directly heated by radiation heat (for example,infrared rays) may be adopted.

Although a configuration in which a region at which the thermoplasticresin material with the reinforcing cord 26 embedded therein is meltedor softened is forcibly cooled with the second roller 64 formed of metalis adopted in Embodiment 1-1, the first aspect of the invention is notlimited to this configuration; a configuration in which cold air isdirectly applied to the region at which the thermoplastic resin materialis melted or softened, to forcibly cool and solidify the region at whichthe thermoplastic resin material is melted or softened may also beadopted.

Although a configuration in which the reinforcing cord 26 is heated isadopted in Embodiment 1-1, a configuration in which the outercircumference of the reinforcing cord 26 is coated with the samethermoplastic resin material as that of the tire case 17, for example,may be adopted. In this case, by heating the coated thermoplastic resinmaterial along with the reinforcing cord 26 when the coated reinforcingcord is wound on the crown portion 16 of the tire case 17, incorporationof air can effectively be suppressed at the time of embedding thereinforcing cord in the crown portion 16.

The tire 10 according to Embodiment 1-1 is a so-called tubeless tire inwhich an air chamber is formed between the tire 10 and the rim 20 byfitting the bead portion 12 to the rim 20. However, the first aspect ofthe invention is not limited to this configuration, and a complete tubeshape may be adopted.

Helically winding the reinforcing cord 26 is easy from the viewpoint ofproduction. However, a method in which the reinforcing cord 26 isdiscontinuous in the width direction, for example, may also becontemplated.

Although modes for carrying out the first aspect of the invention aredescribed above with reference to embodiments, the embodiments aremerely examples, and may be practiced with various modifications withina range that does not depart from the gist of the first aspect. Ofcourse, the protection scope of the first aspect of the invention is notlimited to these embodiments.

Embodiment 1-2

Embodiment 1-2 of the method for producing a tire and the tire accordingto the first aspect of the invention will be described below withreference to the drawings. Similarly to Embodiment 1-1, the tireaccording to this embodiment has substantially the same cross-sectionalshape as those of conventional general rubber pneumatic tires.Accordingly, in the following drawings, the same elements as thosedescribed in Embodiment 1-1 will be designated by the same referencenumerals. FIG. 5A is a cross-sectional view of the tire according toEmbodiment 1-2 taken along the tire width direction, and FIG. 5B is anenlarged view of a cross-section, taken along the tire width direction,of a bead portion in a state in which a rim is fitted to the tireaccording to Embodiment 1-2. FIG. 6 is a cross-sectional view takenalong the tire width direction, which illustrates a region around areinforcing layer of the tire according to Embodiment 1-2.

Similarly to Embodiment 1-1, the tire case 17 of the tire according toEmbodiment 1-2 is formed of a polyamide-based thermoplastic elastomer(“UBESTA XPA9055X1” manufactured by Ube Industries, Ltd. with a meltingpoint of 162° C.). In the tire 200 according to the present embodiment,a reinforcing cord layer 28 (indicated by a dotted line in FIG. 6)constituted by a coated cord member 26B wound in the circumferentialdirection is superposed on the crown portion 16, as shown in FIGS. 5 and6. The reinforcing cord layer 28 constitutes the outer circumferentialportion of the tire case 17, and reinforces the rigidity in thecircumferential direction of the crown portion 16. The outercircumferential surface of the reinforcing cord layer 28 is included theouter circumferential surface 17S of the tire case 17.

The coated cord member 26B is formed by a cord member 26A that hashigher rigidity than the polyamide-based thermoplastic elastomer formingthe tire case 17, and that is coated with a coating resin material 27 asanother member than the polyamide-based thermoplastic elastomer formingthe tire case 17. In regions in which the coated cord member 26Bcontacts the crown portion 16, the coated cord member 26B and the crownportion 16 are bonded (for example, welded, or adhered with an adhesive)to each other.

The elastic modulus of the coating resin material 27 is preferably setto be within a range of 0.1 times to 10 times the elastic modulus of theresin material forming the tire case 17. When the elastic modulus of thecoating resin material 27 is equal to or less than 10 times the elasticmodulus of the thermoplastic resin material forming the tire case 17,the crown portion is not excessively hard, and the fittability to a rimis facilitated. When the elastic modulus of the coating resin material27 is equal to or higher than 0.1 times the elastic modulus of thethermoplastic resin material forming the tire case 17, the resinconstituting the reinforcing cord layer 28 is not excessively soft, andthe in-plane shear stiffness of the belt is excellent, whereby thecornering power. In the present embodiment, the same material (“UBESTAXPA9055X1” manufactured by Ube Industries, Ltd. in the presentembodiment) as the thermoplastic resin material is used as the coatingresin material 27.

As shown in FIG. 6, the coated cord member 26B has a substantiallytrapezoidal cross-sectional shape. In the following description, the topsurface (the outer surface in the tire radial direction) of the coatedcord member 26B is designated by reference numeral 26U, and the bottomsurface (the inner surface in the tire radial direction) is designatedby reference numeral 26D. Although a configuration in which thecross-sectional shape of the coated cord member 26B is substantiallytrapezoidal is adopted in the present embodiment, the first aspect ofthe invention is not limited to this configuration; the cross-sectionalshape of the coated cord member 26B may be any shape other than a shapein which the width increases from the bottom surface 26D side (the innerside in the tire radial direction) to the top surface 26U side (theouter side in the tire radial direction).

As shown in FIG. 6, since coated cord members 26B are arranged withintervals in the circumferential direction, gaps 28A are formed betweenadjacent cord members 26B. Accordingly, the outer circumferentialsurface of the reinforcing cord layer 28 has irregularities, and theouter circumferential surface 17S of the tire case 17 of which the outercircumferential portion is formed of the reinforcing cord layer 28 alsohas irregularities.

Minute roughening irregularities are uniformly formed on the outercircumferential surface 17S (including irregularities) of the tire case17, and a cushion rubber 29 is bonded thereon with a bonding agenttherebetween. The rubber portion at the inner side in the radialdirection of the cushion rubber 29 has flowed into the rougheningirregularities.

A tread 30 formed of a material, such as rubber, having higher abrasionresistance than the resin material forming the tire case 17 is bondedonto the cushion rubber 29 (onto the outer circumferential surface ofthe cushion rubber 29).

The rubber to be used in the tread 30 (a tread rubber 30A) is preferablythe same kind of rubber as the rubber used for conventional rubberpneumatic tires. A tread formed of another kind of resin material havinghigher abrasion resistance than that of the resin material forming thetire case 17 may be used instead of the tread 30. Similarly toconventional rubber pneumatic tires, the tread 30 has a tread pattern(not shown in the drawings) formed by plural grooves on the contactsurface with a road surface.

A method of producing a tire according to the present embodiment will bedescribed below.

(Frame Forming Step)

First, tire case half parts 17A are formed in the same way as inEmbodiment 1-1, and the tire case half parts are heated and pressurizedusing a mold for bonding, thereby forming a tire case 17.

(Reinforcing Cord Member Winding Step)

A tire producing apparatus according to the present embodiment is thesame as in Embodiment 1-1. In the cord feeding apparatus 56 shown inFIG. 3 as described in Embodiment 1-1, a coated cord member 26B whichhas a substantially trapezoidal cross-sectional shape, and which isobtained by coating the cord member 26A with the coating resin material27 (a thermoplastic material in the present embodiment), and which iswound around the reel 58, is used.

First, the temperature of the heater 70 is increased, and the air aroundthe heater 70 heated by the heater 70 is sent to the heating box 74 byan air current generated by the rotation of the fan 72. Then, the coatedcord member 26B drawn out from the reel 58 is fed to the inside of theheating box 74 of which the inner space is heated with hot air, wherebythe reinforcing cord member is heated (for example, to increase thetemperature of the outer circumferential surface of the reinforcing cordmember 26B to be equal to or higher than the melting point of thecoating resin material 27). Here, as a result of the heating of thecoated cord member 26B, the coating resin material 27 becomes melted orsoftened.

The coated cord member 26B passes through the discharge port 76, and ishelically wound, with a constant tension, around the outercircumferential surface of the crown portion 16 of the tire case 17rotating in a direction of approaching from the paper surface. At thistime, the bottom surface 26D of the coated cord member 26B comes intocontact with the outer circumferential surface of the crown portion 16.The melted or softened coating resin material 27 at the contact portionspreads on the outer circumferential surface of the crown portion 16,and the coated cord member 26B is welded to the outer circumferentialsurface of the crown portion 16. Thereby, the bonding strength betweenthe crown portion 16 and the coated cord member 26B is increased.

(Roughening Treatment Step)

Then, in a blasting apparatus not shown in the drawings, a blastingabrasive is shot to the outer circumferential surface 17S of the tirecase 17 while the tire case 17 is rotated. The blasting abrasive thathas been shot collides with the outer circumferential surface 17S toform minute roughening irregularities with an arithmetic averageroughness Ra of 0.05 mm or more on the outer circumferential surface17S.

By forming minute roughening irregularities on the outer circumferentialsurface 17S of the tire case 17 in this manner, the outercircumferential surface 17S is made hydrophilic, and the wettability ofthe below-described adhesive is improved.

(Superposing Step)

A bonding agent is applied to the outer circumferential surface 17S ofthe tire case 17 that has been subjected to the roughening treatment.

The bonding agent is not particularly limited, and may be, for example,a triazine thiol-based adhesive, a chlorinated rubber-based adhesive, aphenol-based resin adhesive, an isocyanate-based adhesive, a halogenatedrubber-based adhesive, a rubber-based adhesive, or the like. The bondingagent is preferably capable of reacting at a temperature (90° C. to 140°C.) at which the cushion rubber 29 can be vulcanized.

A non-vulcanized cushion rubber 29 is wound, for one revolution, on theouter circumferential surface 17S to which the bonding agent has beenapplied, and a bonding agent such as a rubber cement composition isapplied onto the cushion rubber 29. A vulcanized or semi-vulcanizedtread rubber 30A is wound thereon for one revolution, to become to be inthe green tire case state.

(Vulcanization Step)

Then, the green tire case is housed in a vulcanization can or a mold,and is vulcanized. In this recess, unvulcanized cushion rubber 29 flowsinto the roughening irregularities, which have been formed on the outercircumferential surface 17S of the tire case 17 through the rougheningtreatment. Once the vulcanization is completed, an anchor effect isexerted by the cushion rubber 29 that has flowed into the rougheningirregularities, and the bonding strength between the tire case 17 andthe cushion rubber 29 is increased. That is, the bonding strengthbetween the tire case 17 and the tread 30 is enhanced due to thepresence of the cushion rubber 29.

A tire 200 is completed by adhering a sealing layer 24 formed of a softmaterial softer than the resin material to the bead portion 12 of thetire case 17 by using an adhesive or the like.

(Effects)

The tire 200 according to the present embodiment has excellent heatresistance, excellent tensile modulus of elasticity, excellent tensilestrength, and excellent fracture strain since the tire case 17 is formedof the polyamide-based thermoplastic elastomer. In addition, since thestructure thereof is simpler than those of conventional rubber tires,the weight thereof is smaller. Therefore, the tire 200 according to thepresent embodiment has high abrasion resistance and high durability. Thepolyamide-based thermoplastic elastomer constituting the tire case 17has a melting point of 162° C. Thus, the tire case half parts 17A can besufficiently bonded at, for example, about 250° C., and, therefore,energy consumption can be reduced, and the cost required for heating canbe reduced. Further, the polyamide-based thermoplastic elastomer hashigh adhesiveness to the coated cord member 26B.

In a case in which the reinforcing cord layer 28 is configured toinclude the coated cord member 26B as described above, the coated cordmember 26B can be made to more tightly contact the tire case 17 andfixed to the tire case 17 since the difference in hardness between thetire case 17 and the reinforcing cord layer 28 can be made smaller thanthat in a case in which the reinforcing cord 26A is fixed simply byusing the cushion rubber 29. Accordingly, the incorporation of airmentioned above can effectively be prevented, and the movement of thereinforcing cord member at the time of traveling can effectively besuppressed.

In a case in which the reinforcing cord 26A is a steel cord, the cordmember 26A can easily be separated from the coated cord member 26B byheating and recovered at the time of disposing of the tire, and,therefore, there is an advantage from the viewpoint of recyclability ofthe tire 200. Further, since the polyamide-based thermoplastic elastomerhas a lower loss factor (tan δ) compared with vulcanized rubbers,inclusion of a large amount of polyamide-based thermoplastic elastomerin the reinforcing cord layer 28 makes it possible to enhance therolling properties of the tire. Compared with vulcanized rubbers, thepolyamide-based thermoplastic elastomer has advantages in terms of highin-plane shear stiffness, excellent steering stability at the time oftraveling with the tire, and excellent abrasion resistance.

In the method for producing a tire according to the present embodiment,when the tire case 17, the cushion rubber 29, and the tread rubber 30Aare integrated, the bonding properties (adhesion properties) is improvedby the anchor effect since the outer circumferential surface 17S of thetire case 17 has been subjected to the roughening treatment. Further,since the resin material forming the tire case 17 is ploughed due tocollision of the blasting abrasive, the wettability of the bonding agentis improved. Therefore, the bonding agent is retained, in a uniformlyapplied state, on the outer circumferential surface 17S of the tire case17, whereby the bonding strength between the tire case 17 and thecushion rubber 29 can be ensured.

In particular, even in a case in which irregularities are formed on theouter circumferential surface 17S of the tire case 17, a portionsurrounding a recess (walls at the recess, the bottom of the recess) isroughened by allowing the blasting abrasive to collide with the portionsurrounding the recess (the gap 28A), whereby the bonding strengthbetween the tire case 17 and the cushion rubber 29 can be ensured.

Since the cushion rubber 29 is superposed on the roughened area of theouter circumferential surface 17S of the tire case 17, the bondingstrength between the tire case 17 and the cushion rubber can effectivelybe ensured.

In the case of vulcanization of the cushion rubber 29 in thevulcanization step, the cushion rubber 29 flows into the rougheningirregularities that have been formed on the outer circumferentialsurface 17S of the tire case 17 through the roughening treatment. Oncethe vulcanization is completed, an anchor effect is exerted by thecushion rubber 29 that has flowed into the roughening irregularities,and the bonding strength between the tire case 17 and the cushion rubber29 is enhanced.

In the tire 200 produced by the method for producing a tire, the bondingstrength between the tire case 17 and the cushion rubber 29 is ensured.That is, the bonding strength between the tire case 17 and the tread 30is ensured due to the presence of the cushion rubber 29. Therefore,separation between the outer circumferential surface 17S of the tirecase 17 and the cushion rubber 29 in the tire 200 is suppressed at thetime of, for example, traveling.

Since the outer circumferential portion of the tire case 17 is formed ofthe reinforcing cord layer 28, puncture resistance and cuttingresistance are improved, compared with a case in which the outercircumferential portion is formed of a member other than the reinforcingcord layer 28.

Since the coated cord member 26B is wound to form the reinforcing cordlayer 28, the rigidity in the circumferential direction of the tire 200is improved. Since the rigidity in the circumferential direction isimproved, creeping of the tire case 17 (a phenomenon in which theplastic deformation of the tire case 17 increases with lapse of timeunder a constant stress) is suppressed, and pressure resistance to airpressure applied from the inner side in the tire radial direction isimproved.

Although irregularities are formed on the outer circumferential surface17S of the tire case 17 in the present embodiment, the first aspect ofthe invention is not limited to this configuration, and a configurationin which the outer circumferential surface 17S is formed flat may beadopted.

In the tire case 17, a reinforcing cord layer may be formed by covering,with a coating thermoplastic material, the coated cord member that hasbeen wound on the crown portion of the tire case and bonded thereto. Inthis case, the coating layer can be formed by ejecting the coatingthermoplastic material in the melted or softened state onto thereinforcing cord layer 28. The coating layer may be formed without usingan extruder, by heating a welding sheet into a melted or softened state,and attaching the welding sheet to the surface (the outercircumferential surface) of the reinforcing cord layer 28.

Although case divided parts (tire case half parts 17A) are bonded toform the tire case 17 in Embodiment 1-2, the first aspect of theinvention is not limited to this configuration, and the tire case 17 maybe formed as an integrated body using, for example, a mold.

The tire 200 according to Embodiment 1-2 is a so-called tubeless tire inwhich an air chamber is formed between the tire 200 and the rim 20 byfitting the bead portion 12 to the rim 20. However, the first aspect ofthe invention is not limited to this configuration, and the tire 200 mayhave, for example, a complete tube shape.

Although the cushion rubber 29 is interposed between the tire case 17and the tread 30 in Embodiment 1-2, the first aspect of the invention isnot limited to this configuration, and a configuration in which thecushion rubber 29 is not provided may be adopted.

Although a configuration in which the coated cord member 26B ishelically wound on the crown portion 16 is adopted in Embodiment 1-2,the first aspect of the invention is not limited to this configuration,and a configuration in which the coated cord member 26B is wound butdiscontinuous in the width direction may be adopted.

In Embodiment 1-2, a configuration is adopted in which a thermoplasticmaterial is used as the coating resin material 27 that forms the coatedcord member 26B, and in which the coating resin material 27 is melted orsoftened by heating, thereby welding the coated cord member 26B to theouter circumferential surface of the crown portion 16. However, thefirst aspect of the invention is not limited to this configuration, anda configuration in which the coated cord member 26B is adhered to theouter circumferential surface of the crown portion 16 using an adhesiveor the like, without heating the coating resin material 27, may beadopted.

A configuration may be adopted in which the coating resin material 27that forms the coated cord member 26B is a thermosetting resin, and inwhich the coated cord member 26B is adhered to the outer circumferentialsurface of the crown portion 16 using an adhesive or the like, withoutheating the coated cord member 26B.

A configuration may be adopted in which the coating resin material 27that forms the coated cord member 26B is a thermosetting resin, and inwhich the tire case 17 is formed of a thermoplastic resin material. Inthis case, the coated cord member 26B may be adhered to the outercircumferential surface of the crown portion 16 using an adhesive or thelike, or the coated cord member 26B may be welded to the outercircumferential surface of the crown portion 16 by heating a portion ofthe tire case 17 at which the coated cord member 26B is to be disposedto get into a melted or softened state.

A configuration may be adopted in which the coating resin material 27that forms the coated cord member 26B is a thermoplastic material, andin which the tire case 17 is formed of a thermoplastic resin material.In this case, the coated cord member 26B may be adhered to the outercircumferential surface of the crown portion 16 using an adhesive or thelike, or the coated cord member 26B may be welded to the outercircumferential surface of the crown portion 16 by heating a portion ofthe tire case 17 at which the coated cord member 26B is to be disposedto get into a melted or softened state as well as heating the coatingresin material 27 to get into a melted or softened state. In a case inwhich both the tire case 17 and the coated cord member 26B are heated toget into a melted or softened state, both materials mix with each otherwell, thereby increasing the bonding strength. In a case in which eachof the resin material that forms the tire case 17 and the coating resinmaterial 27 that forms the coated cord member 26B is a thermoplasticresin material, the thermoplastic resin materials thereof are preferablythermoplastic resin materials of the same kind, and particularlypreferably the same thermoplastic material.

The outer circumferential surface 17S of the tire case 17 that has beensubjected to the roughening treatment may be subjected to coronatreatment, plasma treatment or the like so as to activate the outercircumferential surface 17S and so as to enhance the hydrophilicity, andan adhesive may thereafter be applied thereto.

The sequence employed in the production of the tire 200 is not limitedto the sequence described in Embodiment 1-2, and may be modified, asappropriate.

Although modes for carrying out the first aspect of the invention aredescribed above with reference to embodiments, the embodiments aremerely examples, and may be practiced with various modifications withina range that does not depart from the gist of the first aspect. Ofcourse, the protection scope of the first aspect of the invention is notlimited to these embodiments.

Although specific modes of the first aspect of the invention aredescribed above with reference to Embodiment 1-1 and Embodiment 1-2, thefirst aspect of the invention is not limited to the modes describedabove.

<<Second Aspect of Invention>>

A thermoplastic resin material that includes a polyamide-basedthermoplastic elastomer and an elastomer other than polyamide-basedthermoplastic elastomer, and that forms a tire frame, and a resinmaterial that forms a reinforcing cord layer in the second aspect of theinvention will be first described, and specific embodiments of a tireaccording to the second aspect of the invention will be then describedwith reference to the accompanying drawings.

[Thermoplastic Resin Including Polyamide-Based Thermoplastic Elastomerand Other Elastomer]

The tire according to the second aspect of the invention has a circulartire frame formed from a thermoplastic resin material containing atleast a polyamide-based thermoplastic elastomer and another elastomer.

Here, as the “polyamide-based thermoplastic elastomer”, thepolyamide-based thermoplastic elastomers as described in the firstaspect of the invention can be used.

The “elastomer other than polyamide-based thermoplastic elastomer”refers to a thermoplastic resin material formed of a copolymer thatincludes a polymer constituting a crystalline hard segment having a highmelting point or a hard segment having a high cohesive force, and anon-crystalline polymer constituting a soft segment having a low glasstransition temperature, in which the polymer constituting the hardsegment is a polymer, other than a polyamide having an amide bond(—CONH—) in the main chain, such as a polyurethane, a polystyrene, apolyolefin, a polyester or the like obtained by polymerizing urethane,styrene, olefin, polyester or the like. Examples of the other elastomerinclude a polyurethane-based thermoplastic elastomer (TPU), apolystyrene-based thermoplastic elastomer (TPS), and a polyolefin-basedthermoplastic elastomer (TPO), and a polyester-based thermoplasticelastomer (TPC) as defined in JIS K6418:2007. From the viewpoint ofpulling-out properties of a reinforcing cord, it is preferable to use apolyurethane-based elastomer as another elastomer.

—Polyurethane-Based Thermoplastic Elastomer—

The polyurethane-based thermoplastic elastomer may be, for example, amaterial in which at least a polyurethane constitutes a hard segmentforming a pseudo-crosslinking by physical aggregation, and in whichanother polymer constitutes a non-crystalline soft segment having a lowglass transition temperature; the polyurethane-based thermoplasticelastomer may be represented as a copolymer including, for example, asoft segment containing a unit structure represented by the followingformula A and a hard segment containing a unit structure represented bythe following formula B.

In the formulae, P represents a long-chain aliphatic polyether or along-chain aliphatic polyester; R represents an aliphatic hydrocarbon,an alicyclic hydrocarbon, or an aromatic hydrocarbon; P′ represents ashort-chain aliphatic hydrocarbon, an alicyclic hydrocarbon, or anaromatic hydrocarbon.

Examples of the long-chain aliphatic polyether represented by P and thelong-chain aliphatic polyester represented by P in Formula A that can beused include those having molecular weights of 500 to 5000. P is derivedfrom a diol compound containing the long-chain aliphatic polyether orlong-chain aliphatic polyester represented by P. Examples of the diolcompound include polyethylene glycol, polypropylene glycol,polytetramethylene ether glycol, poly(butylene adipate) diol,poly-ε-caprolactone diol, poly(hexamethylene carbonate) diol, and theABA-type triblock polyether, each of which has a molecular weight withinthe above range.

These may be used singly, or in combination of two or more thereof.

In Formulae A and B, R is derived from a diisocyanate compoundcontaining the aliphatic hydrocarbon, alicyclic hydrocarbon, or aromatichydrocarbon represented by R. Examples of an aliphatic diisocyanatecompound containing an aliphatic hydrocarbon represented by R include1,2-ethylene diisocyanate, 1,3-propylene diisocyanate, 1,4-butanediisocyanate, and 1,6-hexamethylene diisocyanate.

Furthermore, examples of a diisocyanate compound containing an alicyclichydrocarbon represented by R include 1,4-cyclohexane diisocyanate and4,4-cyclohexane diisocyanate. Further, examples of an aromaticdiisocyanate compound containing an aromatic hydrocarbon represented byR include 4,4′-diphenylmethane diisocyanate and tolylene diisocyanate.

These may be used singly, or in combination of two or more thereof.

Examples of the short-chain aliphatic hydrocarbon, alicyclichydrocarbon, or aromatic hydrocarbon represented by P′ in Formula Binclude those having molecular weights of less than 500. Further, P′ isderived from a diol compound containing the short-chain aliphatichydrocarbon, alicyclic hydrocarbon, or aromatic hydrocarbon representedby P′. Examples of an aliphatic diol compound containing the short-chainaliphatic hydrocarbon represented by P′ include glycols and polyalkyleneglycols, such as ethylene glycol, propylene glycol, trimethylene glycol,1,4-butanediol, 1,3-butanediol, 1,5-pentanediol, 1,6-hexanediol,1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol and 1,10-decanediol.

Examples of an alicyclic diol compound containing the alicyclichydrocarbon represented by P′ include cyclopentane-1,2-diol,cyclohexane-1,2-diol, cyclohexane-1,3-diol, cyclohexane-1,4-diol, andcyclohexane-1,4-dimethanol.

Further, examples of an aromatic diol compound containing the aromatichydrocarbon represented by P′ include hydroquinone, resorcin,chlorohydroquinone, bromohydroquinone, methylhydroquinone,phenylhydroquinone, methoxyhydroquinone, phenoxyhydroquinone,4,4′-dihydroxybiphenyl, 4,4′-dihydroxydiphenyl ether,4,4′-dihydroxydiphenylsulfide, 4,4′-dihydroxydiphenylsulfone,4,4′-dihydroxybenzophenone, 4,4′-dihydroxydiphenylmethane,bisphenolA,1,1-di(4-hydroxyphenyl)cyclohexane,1,2-bis(4-hydroxyphenoxy)ethane, 1,4-dihydroxynaphthalene,2,6-dihydroxynaphthalene, etc.

These may be used singly, or in combination of two or more thereof.

The number average molecular weight of the polymer constituting the hardsegment (polyamide) is preferably from 300 to 1,500, from the viewpointof melt moldability. Further, the number average molecular weight of thepolymer constituting the soft segment is preferably from 500 to 20,000,more preferably from 500 to 5,000, and particularly preferably from 500to 3,000, from the viewpoints of flexibility and thermal stability ofthe polyurethane-based thermoplastic elastomer. Further, the mass ratio(x:y) of the hard segment (x) to the soft segment (y) is preferably from15:85 to 90:10, and more preferably from 30:70 to 90:10, from theviewpoint of moldability.

Specifically, as the polyurethane-based thermoplastic elastomer, acopolymer of tolylene diisocyanate (TDI) and polyester-based polyol, acopolymer of TDI and polyether-based polyol, a copolymer of TDI andcaprolactone-based polyol, a copolymer of TDI and polycarbonate-basedpolyol, a copolymer of 4,4′-diphenylmethane diisocyanate (MDI) andpolyester-based polyol, a copolymer of MDI and polyether-based polyol, acopolymer of MDI and caprolactone-based polyol, and a copolymer of MDIand polycarbonate-based polyol are preferable, and TDI with apolyester-based polyol, TDI with a polyether-based polyol, MDI with apolyester polyol, and MDI with a polyether-based polyol are morepreferable.

The polyurethane-based thermoplastic elastomer can be synthesized bycopolymerizing a polymer for forming the hard segment and a polymer forforming the soft segment according to known methods. Thepolyurethane-based thermoplastic elastomer to be used may be, forexample, a thermoplastic polyurethane described in JP-A No. 5-331256.

Furthermore, examples of the polyurethane-based thermoplastic elastomerthat can be used include commercial products such as ELASTRAN series(for example, ET680, ET880, ET690, ET890, etc.) manufactured by BASFCo., Ltd., KURAMIRON U series (for example, 2000 numbers, 3000 numbers,8000 numbers, and 9000 numbers) manufactured by Kuraray Co., Ltd.,MIRACTRAN series (for example, XN-2001, XN-2004, P390RSUP, P480RSUI,P26MRNAT, E490, E590, and P890) manufactured by Nippon Miractran Co.,Ltd.

—Polystyrene-Based Thermoplastic Elastomer—

The polystyrene-based thermoplastic elastomer may be, for example, amaterial in which at least polystyrene constitutes the hard segment andanother polymer (for example, polybutadiene, polyisoprene, polyethylene,hydrogenated polybutadiene, hydrogenated polyisoprene, or the like)constitutes the non-crystalline soft segment having a low glasstransition temperature. The polystyrene for forming the hard segmentthat can be used may be, for example, a polystyrene obtained by a knownradical polymerization method or ionic polymerization method, andexamples thereof include a polystyrene having anionic livingpolymerization.

Furthermore, examples of the polymer for forming the soft segmentinclude polybutadiene, polyisoprene, and poly(2,3-dimethylbutadiene).

Examples of the combination of the hard segment and the soft segmentdescribed above include any combination of any of the hard segmentsdescribed above and any of the soft segments described above. Amongthese, a combination of polystyrene with polybutadiene, and acombination of polystyrene with polyisoprene are preferable. Further, inorder to suppress undesired crosslinking reaction of the thermoplasticelastomer, the soft segment is preferably a hydrogenated soft segment.

The number average molecular weight of the polymer constituting the hardsegment (polystyrene) is preferably from 5,000 to 500,000, and morepreferably from 10,000 to 200,000.

Furthermore, the number average molecular weight of the polymerconstituting the soft segment is preferably from 5,000 to 1,000,000,more preferably from 10,000 to 800,000, and particularly preferably from30,000 to 500,000. In addition, the mass ratio (x:y) of the hard segment(x) to the soft segment (y) is preferably from 5:95 to 80:20, and morepreferably from 10:90 to 70:30, from the viewpoint of moldability.

The polystyrene-based thermoplastic elastomer can be synthesized bycopolymerizing a polymer for forming the hard segment and a polymer forforming the soft segment according to known methods.

Examples of the polystyrene-based thermoplastic elastomer include astyrene-butadiene-based copolymer [SBS (polystyrene-poly(butylene)block-polystyrene), a SEBS (polystyrene-poly(ethylene/butylene)block-polystyrene)], a styrene-isoprene copolymer[polystyrene-polyisoprene block-polystyrene), a styrene-propylene-basedcopolymer [SEP (polystyrene-(ethylene/propylene) block), a SEPS(polystyrene-poly(ethylene/propylene) block-polystyrene), an SEEPS(polystyrene-poly(ethylene-ethylene/propylene) block-polystyrene)), andan SEB (polystyrene (ethylene/butylene) block).

Examples of polystyrene-based thermoplastic elastomer that can be usedinclude commercial products such as TAFTEC series (for example, H1031,H1041, H1043, H1051, H1052, H1053, H1082, H1141, H1221, and H1272)manufactured by Asahi Kasei Corporation; and SEBS (8007, 8076, etc.) andSEPS (2002, 2063, etc.) manufactured by Kuraray.

—Polyolefin-Based Thermoplastic Elastomer—

The polyolefin-based thermoplastic elastomer may be, for example, amaterial in which at least polyolefin constitutes a crystalline hardsegment having a high melting point, and in which another polymer (forexample, any of the polyolefins described above, or another polyolefinor polyvinyl compound) constitutes a non-crystalline soft segment havinga low glass transition temperature. Examples of the polyolefin thatforms the hard segment include polyethylene, polypropylene, isotacticpolypropylene, polybutene, etc.

Examples of the polyolefin-based thermoplastic elastomer include anolefin-α-olefin random copolymer and an olefin block copolymer, such asa propylene block copolymer, a copolymer of ethylene and propylene, acopolymer of propylene and 1-hexene, a copolymer of propylene and4-methyl-1-pentene, a copolymer of propylene and 1-butene, a copolymerof ethylene and 1-hexene, a copolymer of ethylene and 4-methyl-pentene,a copolymer of ethylene and 1-butene, a copolymer of 1-butene and1-hexene, a copolymer of 1-butene and 4-methyl-pentene, a copolymer ofethylene and methacrylic acid, a copolymer of ethylene and methylmethacrylate, a copolymer of ethylene and ethyl methacrylate, acopolymer of ethylene and butyl methacrylate, a copolymer of ethyleneand methyl acrylate, a copolymer of ethylene and ethyl acrylate, acopolymer of ethylene and butyl acrylate, a copolymer of propylene andmethacrylic acid, a copolymer of propylene and methyl methacrylate, acopolymer of propylene and ethyl methacrylate, a copolymer of propyleneand butyl methacrylate, a copolymer of propylene and methyl acrylate, acopolymer of propylene and ethyl acrylate, a copolymer of propylene andbutyl acrylate, a copolymer of ethylene and vinyl acetate, and acopolymer of propylene and vinyl acetate.

The polyolefin-based thermoplastic elastomer is preferably a propyleneblock copolymer, a copolymer of ethylene and propylene, a copolymer ofpropylene and 1-hexene, a copolymer of propylene and 4-methyl-1-pentene,a copolymer of propylene and 1-butene, a copolymer of ethylene and1-hexene, a copolymer of ethylene and 4-methyl-pentene, a copolymer ofethylene and 1-butene, a copolymer of ethylene and methacrylic acid, acopolymer of ethylene and methyl methacrylate, a copolymer of ethyleneand ethyl methacrylate, a copolymer of ethylene and butyl methacrylate,a copolymer of ethylene and methyl acrylate, a copolymer of ethylene andethyl acrylate, a copolymer of ethylene and butyl acrylate, a copolymerof propylene and methacrylic acid, a copolymer of propylene and methylmethacrylate, a copolymer of propylene and ethyl methacrylate, acopolymer of propylene and butyl methacrylate, a copolymer of propyleneand methyl acrylate, a copolymer of propylene and ethyl acrylate, acopolymer of propylene and butyl acrylate, a copolymer of ethylene andvinyl acetate, or a copolymer of propylene and vinyl acetate, and morepreferably a copolymer of ethylene and propylene, a copolymer ofpropylene and 1-butene, a copolymer of ethylene and 1-butene, acopolymer of ethylene and methyl methacrylate, a copolymer of ethyleneand methyl acrylate, a copolymer of ethylene and ethyl acrylate, or acopolymer of ethylene and butyl acrylate.

Two or more polyolefin resins, such as ethylene and propylene, may beused in combination. The content of polyolefin in the polyolefin-basedthermoplastic elastomer is preferably from 50% by mass to 100% by mass.

The number average molecular weight of the polyolefin-basedthermoplastic elastomer is preferably from 5,000 to 10,000,000. When thenumber average molecular weight of the polyolefin-based thermoplasticelastomer is in the range of 5,000 to 10,000,000, the thermoplasticresin material has sufficient mechanical properties, and excellentprocessability. From similar viewpoints, the number average molecularweight is more preferably from 7,000 to 1,000,000, and particularlypreferably from 10,000 to 1,000,000. Within these ranges, the mechanicalproperties and processability of the thermoplastic resin material canfurther be improved. Further, the number average molecular weight of thepolymer constituting the soft segment is preferably from 200 to 6,000from the viewpoint of toughness and low-temperature flexibility.Further, the mass ratio (x:y) of the hard segment (x) to the softsegment (y) is preferably from 50:50 to 95:15, and more preferably from50:50 to 90:10, from the viewpoint of moldability.

The polyolefin-based thermoplastic elastomer can be synthesized bycopolymerization using known methods.

Examples of polyolefin-based thermoplastic elastomers that can be usedinclude commercial products such as: TAFMER series (for example, A0550S,A1050S, A4050S, A1070S, A4070S, A35070S, A1085S, A4085S, A7090, A70090,MH7007, MH7010, XM-7070, XM-7080, BL4000, BL2481, BL3110, BL3450,P-0275, P-0375, P-0775, P-0180, P-0280, P-0480, and P-0680) manufacturedby Mitsui Chemicals, Inc.; NUCREL series (for example, AN4214C, AN4225C,AN42115C, N0903HC, N0908C, AN42012C, N410, N1050H, N1108C, N1110H,N1207C, N1214, AN4221C, N1525, N1560, N0200H, AN4228C, AN4213C, andN035C) and ELVALOY AC series (for example, 1125AC, 1209AC, 1218AC,1609AC, 1820AC, 1913AC, 2112AC, 2116AC, 2615AC, 2715AC, 3117AC, 3427AC,3717AC) manufactured by DU PONT-MITSUI POLY CHEMICALS CO., LTD.; ACRYFTseries and EVATATE series manufactured by Sumitomo Chemical Co., Ltd.;ULTRASON series manufactured by Tosoh Corporation; etc.

Further examples of polyolefin-based thermoplastic elastomer that can beused include commercial available products PRIME TPO series (forexample, E-2900 H, F-3900 H, E-2900, F-3900, J-5900, E-2910, F-3910,J-5910, E-2710, F-3710, J-5910, E-2740, F-3740, R110 MP, R110E, T310E,M142E, etc) manufactured by Prime Polymer Co., Ltd., etc.

—Polyester-Based Thermoplastic Elastomer—

The polyester-based thermoplastic elastomer may be, for example, amaterial in which at least polyester constitutes the hard segment, andin which another polymer (for example, polyester, polyether, or thelike) constitutes the non-crystalline soft segment having a low glasstransition temperature.

The polyester for forming the hard segment to be used may be an aromaticpolyester. The aromatic polyester can be formed from, for example, anaromatic dicarboxylic acid or ester-forming derivative thereof and analiphatic diol. The aromatic polyester is preferably a polybutyleneterephthalate derived from terephthalic acid and/or dimethylterephthalate and 1,4-butanediol. Further, the aromatic polyester may bea polyester derived from a dicarboxylic acid component such asisophthalic acid, phthalic acid, naphthalene-2,6-dicarboxylic acid,naphthalene-2,7-dicarboxylic acid, diphenyl-4,4′-dicarboxylic acid,diphenoxyethane dicarboxylic acid, 5-sulfoisophthalic acid, or anester-forming derivative thereof, and a diol having a molecular weightof 300 or less. Examples of the diol having a molecular weight of 300 orless include: aliphatic diols such as ethylene glycol, trimethyleneglycol, pentamethylene glycol, hexamethylene glycol, neopentyl glycol,and decamethylene glycol; alicyclic diols such as1,4-cyclohexanedimethanol and tricyclodecanedimethylol; and aromaticdiols such as xylylene glycol, bis(p-hydroxy)diphenyl,bis(p-hydroxyphenyl)propane, 2,2-bis[4-(2-hydroxyethoxy)phenyl]propane,bis[4-(2-hydroxy)phenyl]sulfone,1,1-bis[4-(2-hydroxyethoxy)phenyl]cyclohexane,4,4′-dihydroxy-p-terphenyl, and 4,4′-dihydroxy-p-quarterphenyl. Thearomatic polyester may alternatively be a copolymerization polyesterformed using two or more of these dicarboxylic acid components and/ortwo or more of these diol components. Further, polyfunctional carboxylicacid components, polyfunctional oxyacid components, polyfunctionalhydroxy components, etc, each of which is tri- or higher-functional, maybe copolymerized in an amount in the range of 5% by mol or less.

Examples of the polyester for forming the hard segment includepolyethylene terephthalate, polybutylene terephthalate, polymethyleneterephthalate, polyethylene naphthalate, and polybutylene naphthalate.Polybutylene terephthalate is preferable.

Furthermore, examples of the polymer for forming the soft segmentinclude aliphatic polyesters and aliphatic polyethers.

Examples of aliphatic polyethers include poly(ethylene oxide) glycol,poly(propylene oxide) glycol, poly(tetramethylene oxide) glycol,poly(hexamethylene oxide) glycol, a copolymer of ethylene oxide andpropylene oxide, an ethylene oxide adduct polymer of poly(propyleneoxide) glycol, and a copolymer of ethylene oxide and tetrahydrofuran.

Examples of aliphatic polyesters include poly(ε-caprolactone),polyenantholactone, polycaprylolactone, polybutylene adipate, andpolyethylene adipate.

Among these aliphatic polyethers and aliphatic polyesters,poly(tetramethylene oxide) glycol, an ethylene oxide adduct ofpoly(propylene oxide) glycol, poly(ε-caprolactone), polybutyleneadipate, polyethylene adipate, etc. are preferable from the viewpoint ofthe elastic characteristics of the resultant polyester block copolymer.

The number average molecular weight of the polymer(polyester) forforming the hard segment is preferably from 300 to 6,000 from theviewpoint of toughness and low-temperature flexibility. Further, thenumber average molecular weight of the polymer for forming the softsegment is preferably from 300 to 6,000 from the viewpoint of toughnessand low-temperature flexibility. The volume ratio (a:b) of the hardsegment (a) to the soft segment (b) is preferably from 99:1 to 20:80,and more preferably from 98:2 to 30:70, from the viewpoint ofmoldability.

The other elastomer mentioned above can be synthesized by copolymerizinga polymer for forming the hard segment and a polymer for forming thesoft segment according to known methods.

The polyester-based thermoplastic elastomer can be synthesized bycopolymerizing a polymer for forming the hard segment and a polymer forforming the soft segment according to known methods.

Commercially available products may be used as the polyester-basedthermoplastic elastomer. For example, HYTREL series (for example, 3046,5557, 6347, 4047, 4767) manufactured by DU PONT-TORAY CO., LTD.,PELPRENE series (for example, P30B, P40B, P40H, P55B, P70B, P150B,P250B, E450B, P150 M, S1001, S2001, S5001, S6001, S9001) manufactured byTOYOBO CO., LTD., etc., may be used.

A product obtained by acid-modifying a thermoplastic elastomer otherthan polyamide-based thermoplastic elastomer may be used.

The “product obtained by acid-modifying a thermoplastic elastomer otherthan polyamide-based thermoplastic elastomer” refer to a productobtained by boding an unsaturated compound having an acidic group suchas a carboxylic acid group, a sulfuric acid group, or a phosphoric acidgroup to the other thermoplastic elastomer. For example, in the case ofusing an unsaturated carboxylic acid (generally, anhydrous maleic acid)as an unsaturated compound having an acidic group, unsaturated bondingsites of the unsaturated carboxylic acid may be bonded to anolefin-based thermoplastic elastomer (by, for example, graftpolymerization).

The compound having an acidic group is preferably a compound having acarboxylic acid group that is a weakly acidic group, from the viewpointof suppression of deterioration of the polyamide-based thermoplasticelastomer and the thermoplastic elastomer other than polyamide-basedthermoplastic elastomer, and examples thereof include acrylic acid,methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, andmaleic acid.

Commercially available products, for example, may be used as the otherelastomer.

Commercially available products may be used as the polyurethane-basedthermoplastic elastomer, such as ELASTRAN series (for example, ET680,ET880, ET690, and ET890) manufactured by BASF Co., Ltd., KURAMIRON Useries (for example, 2000 numbers, 3000 numbers, 8000 numbers, and 9000numbers) manufactured by Kuraray Co., Ltd., and MIRACTRAN series (forexample, XN-2001, XN-2004, P390RSUP, P480RSUI, P26MRNAT, E490, E590, andP890) manufactured by Nippon Miractran Co., Ltd.

Commercially available products may be used as the polystyrene-basedthermoplastic elastomer, such as TAFTEC series (for example, H1031,H1041, H1043, H1051, H1052, H1053, H1082, H1141, H1221, and H1272)manufactured by Asahi Kasei Corporation, and SEBS (8007, 8076, etc.) andSEPS (2002, 2063, etc.) manufactured by Kuraray.

Commercially available products may be used as the polyolefin-basedthermoplastic elastomer, such as: TAFMER series (for example, A0550S,A1050S, A4050S, A1070S, A4070S, A35070S, A1085S, A4085S, A7090, A70090,MH7007, MH7010, XM-7070, XM-7080, BL4000, BL2481, BL3110, BL3450,P-0275, P-0375, P-0775, P-0180, P-0280, P-0480, and P-0680) manufacturedby Mitsui Chemicals, Inc.; NUCREL series (for example, AN4214C, AN4225C,AN42115C, N0903HC, N0908C, AN42012C, N410, N1050H, N1108C, N1110H,N1207C, N1214, AN4221C, N1525, N1560, N0200H, AN4228C, AN4213C, andN035C) and ELVALOY AC series (for example, 1125AC, 1209AC, 1218AC,1609AC, 1820AC, 1913AC, 2112AC, 2116AC, 2615AC, 2715AC, 3117AC, 3427AC,and 3717AC), manufactured by DU PONT-MITSUI POLY CHEMICALS CO., LTD.;ACRYFT series and EVATATE series manufactured by Sumitomo Chemical Co.,Ltd.; and ULTRASON series manufactured by Tosoh Corporation.

Commercially available products such as PRIME TPO series (for example,E-2900 H, F-3900 H, E-2900, F-3900, J-5900, E-2910, F-3910, J-5910,E-2710, F-3710, J-5910, E-2740, F-3740, R110 MP, R110E, T310E, andM142E) manufactured by Prime Polymer Co., Ltd. may also be used as thepolyolefin-based thermoplastic elastomer.

Commercially available products may be used as the polyester-basedthermoplastic elastomer, such as HYTREL series (for example, 3046, 5557,6347, 4047, 4767) manufactured by DU PONT-TORAY CO., LTD., and PELPRENEseries (for example, P30B, P40B, P40H, P55B, P70B, P150B, P280B, P450B,P150 M, S1001, S2001, S5001, S6001, and 59001) manufactured by TOYOBOCO., LTD.

The mass ratio (x:y) of the polyamide-based thermoplastic elastomer (x)to the other elastomer (y) in the thermoplastic resin is preferably from95:5 to 60:40. When the mass ratio of these elastomers is in the rangeof 95:5 to 60:40, the polyamide-based elastomer and the other elastomerform a sea-island structure in which are polyamide-based thermoplasticelastomer serves as sea, and, therefore, the elastic modulus of the tirecan easily be controlled while maintaining the weldability between thereinforcing cord member and the tire frame by the polyamide-basedthermoplastic elastomer, and the durability and impact resistance of thetire can both be obtained. The mass ratio (x:y) of the polyamide-basedthermoplastic elastomer (x) to the other elastomer (y) is morepreferably from 90:10 to 60:40. In the case of using two or more otherelastomers in combination, the total amount of the other elastomers andthe total amount of the polyamide-based thermoplastic elastomer form aratio within the range described above.

The melting point of the thermoplastic resin containing thepolyamide-based thermoplastic elastomer and the other elastomer isusually about 100° C. to about 350° C., preferably about 100 to about250° C., and more preferably 120° C. to 200° C., from the viewpoint ofthe productivity of tires. In a case in which a thermoplastic resinmaterial containing the polyamide-based thermoplastic elastomer and theother elastomer and having a melting point of 100 to 200° C. asdescribed above is used, and in which, for example, a tire frame isformed by fusing divided parts (frame pieces) thereof, the heatingtemperature of bonding sections can be set to be equal to or higher thanthe melting point of the thermoplastic resin material that forms thetire frame. Since the thermoplastic resin material containing thepolyamide-based thermoplastic elastomer and the other elastomer is usedin the tire according to the second aspect of the invention, the bondingstrength between the tire frame pieces is sufficient even in the case ofa frame fused in the temperature range of 100° C. to 250° C. Therefore,the tire according to the second aspect of the invention has excellentdurability at the time of traveling, such as puncture resistance andabrasion resistance. Further, the heating temperature is preferably atemperature 10° C. to 150° C. higher than, more preferably a temperature10° C. to 100° C. higher than, the melting point of the thermoplasticresin material that contains the polyamide-based thermoplastic elastomerand the other elastomer, and that forms the tire frame pieces.

Furthermore, in the second aspect of the invention, the total content ofthe polyamide-based thermoplastic elastomer and the other elastomer inthe thermoplastic resin material is not particularly limited, and ispreferably from 50% by mass to 100% by mass, more preferably from 90% bymass to 100% by mass, with respect to the total amount of thethermoplastic resin material. When the total content of thepolyamide-based thermoplastic elastomer and the other elastomer is from50% by mass to 100% by mass with respect to the total amount of thethermoplastic resin material, the characteristics of each elastomer canbe sufficiently exhibited, and the durability or productivity of thetire can be improved. The thermoplastic resin material may contain, ifdesired, rubber, other thermoplastic elastomers, thermoplastic resins,various fillers (for example, silica, calcium carbonate, and clay), andvarious additives such as anti-aging agents, oil, plasticizers,colorants, weather resistant agents, and reinforcing agents.

The resin material can be obtained by compounding the thermoplasticelastomer with the specific resin, adding, if necessary, variousadditives, and carrying out mixing, as appropriate, using known methods(for example, melt-mixing). The thermoplastic resin material obtained bythe melt-mixing may be used after shaped into a pellet shape, ifnecessary.

In the second aspect of the invention, the tensile modulus of elasticityas defined in JIS K7113:1995 of the thermoplastic resin materialcontaining the polyamide-based thermoplastic elastomer and the otherelastomer is preferably from 100 MPa to 1000 MPa, more preferably from100 MPa to 800 MPa, and particularly preferably from 100 MPa to 700 MPa.When the tensile modulus of elasticity of the thermoplastic resinmaterial is from 100 to 1000 MPa, fitting to a rim can be efficientlycarried out while maintaining the shape of the tire frame.

In the second aspect of the invention, the tensile strength at yield asdefined in JIS K7113:1995 of the thermoplastic resin material containingthe polyamide-based thermoplastic elastomer and the other elastomer ispreferably 5 MPa or more, more preferably from 5 MPa to 20 MPa, and evenmore preferably from 5 MPa to 17 MPa. When the tensile strength at yieldof the thermoplastic resin material is 5 MPa or more, deformation due toa load applied to the tire at the time of traveling or the like can betolerated.

In the second aspect of the invention, the tensile elongation at yieldas defined in JIS K7113:1995 of the thermoplastic resin materialcontaining the polyamide-based thermoplastic elastomer and the otherelastomer is preferably 10% or more, more preferably from 10 to 70%, andeven more preferably from 15 to 60%. When the tensile elongation atyield of the thermoplastic resin material is 10% or more, the elasticregion is large, and fittability to a rim can be improved.

In the second aspect of the invention, the tensile elongation at breakas defined in JIS K7113:1995 of the thermoplastic resin materialcontaining the polyamide-based thermoplastic elastomer and the otherelastomer is preferably 50% or more, more preferably 100% or more, evenmore preferably 150% or more, and particularly preferably 200% or more.When the tensile elongation at break of the thermoplastic resin materialis 50% or more, fittability to a rim is excellent, and resistance tobreak at collision can be enhanced.

In the second aspect of the invention, the deflection temperature underload (under a load of 0.45 MPa) as defined in ISO75-2 or ASTM D648 ofthe thermoplastic resin material containing the polyamide-basedthermoplastic elastomer and the other elastomer is preferably 50° C. orhigher, more preferably 50 to 150° C., and particularly preferably 50 to130° C. When the deflection temperature under load of the thermoplasticresin material is 50° C. or higher, deformation of the tire frame can besuppressed even when vulcanization is performed during the production ofthe tire.

[Resin Material as Component of Reinforcing Cord Layer]

The tire according to the second aspect of the invention can beconfigured to include a resin material in the reinforcing cord layer.

The [Resin Material as Component of Reinforcing Cord Layer] according tothe second aspect of the invention is the same as the [Resin Material asComponent of Reinforcing Cord Layer] according to the first aspect ofthe invention described above.

Embodiment 2-1

Hereinafter, a tire according to Embodiment 2-1 of the tire according tothe second aspect of the invention will be described with reference tothe drawings.

The tire according to Embodiment 2-1 is the same as the tire accordingto Embodiment 1-1 described above, except for the points discussedbelow. Therefore, the same or corresponding figures and members will bedescribed using the same reference characters and figures.

The tire case 17 in the present embodiment is formed of a thermoplasticresin material containing a polyamide-based thermoplastic elastomer(UBESTA XPA9055X1 manufactured by Ube Industries, Ltd., melting point:162° C.) and a polyurethane-based thermoplastic elastomer (ET680manufactured by BASF Co., Ltd., softening point: 107° C.) in a massratio of 75:25. The other details are the same as those of the tireaccording to Embodiment 1-1 described above, and the production methodtherefor is also the same.

(Effects)

The tire 10 according to the present embodiment has excellent heatresistance, excellent tensile modulus of elasticity, excellent tensilestrength, and excellent fracture strain since the tire case 17 is formedof a thermoplastic resin material containing a polyamide-basedthermoplastic elastomer and a polyurethane-based thermoplasticelastomer. In addition, since the structure is simpler than those ofconventional rubber tires, the weight thereof is smaller. Therefore, thetire 10 according to the present embodiment has high impact resistance,and has high abrasion resistance and high durability. The thermoplasticresin material that constitutes the tire case 17 and contains thepolyamide-based thermoplastic elastomer and the polyurethane-basedthermoplastic elastomer has a melting point or a softening point of 200°C. or lower. Thus, the tire case half parts 17A can be sufficientlybonded at, for example, 250° C. or lower, and, therefore, energyconsumption can be reduced, and the cost required for heating can bereduced.

The thermoplastic resin material containing the polyamide-basedthermoplastic elastomer and the polyurethane-based thermoplasticelastomer has high adhesiveness to the reinforcing cord 26, and hasexcellent fixing performance such as welding strength. Therefore, aphenomenon (incorporation of air) in which air remains around thereinforcing cord 26 can be suppressed in the reinforcing cord windingstep. The high adhesiveness and weldability to the reinforcing cord 26and suppression of incorporation of air into a region around thereinforcing cord member effectively suppresses movement of thereinforcing cord 26 at the time a force is applied during traveling.Accordingly, for example, even in a case in which tire component membersare disposed on the outer circumference of the tire frame so as to coverthe entire reinforcing cord member, the movement of the reinforcing cordmember is suppressed, whereby separation between the members (includingthe tire frame), for example, is suppressed, and the durability of thetire 10 is improved.

In the tire 10 according to the present embodiment, since thereinforcing cord 26 having higher rigidity than that of thethermoplastic resin material is helically wound on the outercircumferential surface of the crown portion 16 of the tire case 17formed of a thermoplastic resin material in the circumferentialdirection, puncture resistance, cutting resistance, and rigidity in thecircumferential direction of the tire 10 are improved. The improvedrigidity in the circumferential direction of the tire 10 preventscreeping of the tire case 17 formed of a thermoplastic resin material.

In a cross-sectional view taken along the axial direction of the tirecase 17 (the cross-section shown in FIG. 1), at least a part of thereinforcing cord 26 is embedded in the outer circumferential surface ofthe crown portion 16 of the tire case 17 formed of the thermoplasticresin material, and is in close contact with the thermoplastic resinmaterial, as a result of which incorporation of air during production issuppressed, and movement of the reinforcing cord 26 due to, for example,a force applied at the time of traveling is suppressed. Accordingly,separation between the reinforcing cord 26, the tire case 17, and thetread 30 is suppressed, and the durability of the tire 10 is improved.

In a case in which the reinforcing cord layer 28 is configured toinclude the polyamide-based thermoplastic elastomer and thepolyurethane-based thermoplastic elastomer as described above, thereinforcing cord 26 can be made to more tightly contact the tire case 17and fixed to the tire case 17 since the difference in hardness betweenthe tire case 17 and the reinforcing cord layer 28 can be made smallerthan that in a case in which the reinforcing cord 26 is fixed using acushion rubber. Accordingly, the incorporation of air mentioned abovecan effectively be prevented, and the movement of the reinforcing cordmember at the time of traveling can effectively be suppressed.

In a case in which the reinforcing cord 26 is a steel cord, thereinforcing cord 26 can easily be separated from the thermoplastic resinmaterial by heating and recovered at the time of disposing of the tire,and, therefore, there is an advantage from the viewpoint ofrecyclability of the tire 10. Further, since the polyamide-basedthermoplastic elastomer has a lower loss factor (tan δ) compared withvulcanized rubbers, inclusion of a large amount of polyamide-basedthermoplastic elastomer in the reinforcing cord layer 28 makes itpossible to enhance the rolling properties of the tire. Compared withvulcanized rubbers, the polyamide-based thermoplastic elastomer hasadvantages in terms of high in-plane shear stiffness, excellent steeringstability at the time of traveling with the tire, and excellent abrasionresistance.

As shown in FIG. 2, since the depth L of embedding of the reinforcingcord 26 is set to be equal to or greater than ⅕ of the diameter Dthereof, incorporation of air during production is effectivelysuppressed, and movement of the reinforcing cord 26 due to a forceapplied at the time of traveling is further suppressed.

Since the tread 30 that contacts a road surface is formed of a rubbermaterial having higher abrasion resistance than that of thethermoplastic resin material constituting the tire case, the abrasionresistance of the tire 10 is improved.

Since the annular bead core 18 formed of a metal material is embedded inthe bead portion 12, the tire case 17 is strongly fixed to the rim 20,i.e., the tire 10 is strongly fixed to the rim 20, similarly toconventional rubber pneumatic tires.

Since the sealing layer 24 formed of a rubber material having highersealing ability than the thermoplastic resin material constituting thetire case is disposed in a region of the bead portion 12 that contactsthe rim 20, the sealing between the tire 10 and the rim 20 is improved.Therefore, compared with a case in which sealing is carried out with therim 20 and the polyamide-based thermoplastic elastomer, air leakage fromthe tire is further suppressed. Further, provision of the sealing layer24 also improves fittability to a rim.

Although a configuration in which the reinforcing cord 26 is heated suchthat the polyamide-based thermoplastic elastomer in a portion thatcontacts the heated reinforcing cord 26 is melted or softened is adoptedin the embodiment described above, the second aspect of the invention isnot limited to this configuration; a hot air generating apparatus may beused, instead of heating the reinforcing cord 26, to heat the outercircumferential surface of the crown portion 16 in which the reinforcingcord 26 is to be embedded, and the reinforcing cord 26 may thereafter beembedded in the crown portion 16.

Although the heat source of the cord heating device 59 includes theheater and the fan in Embodiment 2-1, the second aspect of the inventionis not limited to this configuration, and a configuration in which thereinforcing cord 26 is directly heated by radiation heat (for example,infrared rays) may be adopted.

Although a configuration in which a region at which the thermoplasticresin material with the reinforcing cord 26 embedded therein is meltedor softened is forcibly cooled with the second roller 64 formed of metalis adopted in in Embodiment 2-1, the second aspect of the invention isnot limited to this configuration; a configuration in which cold air isdirectly applied to the region at which the thermoplastic resin materialis melted or softened, to forcibly cool and solidify the region at whichthe thermoplastic resin material is melted or softened may also beadopted.

Although a configuration in which the reinforcing cord 26 is heated isadopted in Embodiment 2-1, a configuration in which the outercircumference of the reinforcing cord 26 is coated with the samethermoplastic resin material as that of the tire case 17, for example,may be adopted. In this case, by heating the coated thermoplastic resinmaterial along with the reinforcing cord 26 when the coated reinforcingcord is wound on the crown portion 16 of the tire case 17, incorporationof air can effectively be suppressed at the time of embedding thereinforcing cord in the crown portion 16.

The tire 10 according to Embodiment 2-1 is a so-called tubeless tire inwhich an air chamber is formed between the tire 10 and the rim 20 byfitting the bead portion 12 to the rim 20. However, the second aspect ofthe invention is not limited to this configuration, and a complete tubeshape may be adopted.

Helical winding the reinforcing cord 26 is easy from the viewpoint ofproduction. However, a method in which the reinforcing cord 26 isdiscontinuous in the width direction, for example, may also becontemplated.

Although modes for carrying out the second aspect of the invention aredescribed above with reference to embodiments, the embodiments aremerely examples, and may be practiced with various modifications withina range that does not depart from the gist of the second aspect. Ofcourse, the protection scope of the second aspect of the invention isnot limited to these embodiments.

Embodiment 2-2

A method for producing a tire according to the second aspect of theinvention, and a tire according to Embodiment 2-2 will be describedbelow with reference to the drawings. Similarly to Embodiment 2-1, thetire according to the present embodiment has substantially the samecross-sectional shape as those of conventional general rubber pneumatictires.

The tire according to Embodiment 2-2 is the same as the tire accordingto Embodiment 1-2 described above, except for the points discussedbelow. Therefore, the same or corresponding figures and members will bedescribed using the same reference characters and figures.

Similarly to Embodiment 2-1, the tire according to Embodiment 2-2 isconfigured such that the tire case 17 is formed of a thermoplastic resinmaterial containing a polyamide-based thermoplastic elastomer (UBESTAXPA9055X1 manufactured by Ube Industries, Ltd., melting point: 162° C.)and a polyurethane-based thermoplastic elastomer (ET680 manufactured byBASF Co., Ltd., softening point: 107° C.) in a mass ratio of 75:25. Theother details are the same as those of the tire according to Embodiment1-2 described above, and the production method therefor is also thesame.

In the present embodiment, the same material (the mixture of thepolyamide-based thermoplastic elastomer (UBESTA XPA9055X1 manufacturedby Ube Industries, Ltd.) and the polyurethane-based thermoplasticelastomer (ET680 manufactured by BASF Co., Ltd.) in a mass ratio of75:25) as the thermoplastic resin material is used as the coating resinmaterial 27.

(Effects)

The tire 200 according to the present embodiment has excellent heatresistance, excellent tensile modulus of elasticity, excellent tensilestrength, and excellent fracture strain since the tire case 17 is formedof a thermoplastic resin material containing a polyamide-basedthermoplastic elastomer and a polyurethane-based thermoplasticelastomer. In addition, since the structure is simpler than those ofconventional rubber tires, the weight thereof is smaller. Therefore, thetire 200 according to the present embodiment has high impact resistance,and has high abrasion resistance and high durability. In thethermoplastic resin material that constitutes the tire case 17, thepolyamide-based thermoplastic elastomer having a higher melting pointfrom among the elastomers contained in the thermoplastic resin materialhas a melting point of 162° C. Thus, the tire case half parts 17A can besufficiently bonded at, for example, 250° C. or lower, and, therefore,energy consumption can be reduced, and the cost required for heating canbe reduced. The polyamide-based thermoplastic elastomer has highadhesiveness to the coated cord member 26B.

In a case in which the reinforcing cord layer 28 is configured toinclude the coated cord member 26B as described above, the coated cordmember 26B can be made to more tightly contact the tire case 17 andfixed to the tire case 17 since the difference in hardness between thetire case 17 and the reinforcing cord layer 28 can be made smaller thanthat in a case in which the reinforcing cord 26A is fixed using thecushion rubber 29. Accordingly, the incorporation of air mentioned abovecan effectively be prevented, and the movement of the reinforcing cordmember at the time of traveling can effectively be suppressed.

In a case in which the reinforcing cord 26A is a steel cord, the cordmember 26A can easily be separated from the coated cord member 26B byheating and recovered at the time of disposing of the tire, and,therefore, there is an advantage from the viewpoint of recyclability ofthe tire 200. Since the polyamide-based thermoplastic elastomer has alower loss factor (tan δ) compared with vulcanized rubbers, inclusion ofa large amount of polyamide-based thermoplastic elastomer in thereinforcing cord layer 28 makes it possible to enhance the rollingproperties of the tire. Compared with vulcanized rubbers, thepolyamide-based thermoplastic elastomer has advantages in terms of highin-plane shear stiffness, excellent steering stability at the time oftraveling with the tire, and excellent abrasion resistance.

In the method for producing a tire according to the present embodiment,when the tire case 17, the cushion rubber 29, and the tread rubber 30Aare integrated, the bonding properties (adhesion properties) is improvedby the anchor effect since the outer circumferential surface 17S of thetire case 17 has been subjected to the roughening treatment. Further,since the resin material forming the tire case 17 is ploughed due tocollision of the blasting abrasive, the wettability of the bonding agentis improved. Therefore, the bonding agent is retained, in a uniformlyapplied state, on the outer circumferential surface 17S of the tire case17, whereby the bonding strength between the tire case 17 and thecushion rubber 29 can be ensured.

In particular, even in a case in which irregularities are formed on theouter circumferential surface 17S of the tire case 17, a portionsurrounding a recess (walls at the recess, the bottom of the recess) isroughened by allowing the blasting abrasive to collide with the portionsurrounding the recess (the gap 28A), whereby the bonding strengthbetween the tire case 17 and the cushion rubber 29 can be ensured.

Since the cushion rubber 29 is superposed on the roughened area of theouter circumferential surface 17S of the tire case 17, the bondingstrength between the tire case 17 and the cushion rubber can effectivelybe ensured.

In the case of vulcanization of the cushion rubber 29 in thevulcanization step, the cushion rubber 29 flows into the rougheningirregularities that have been formed on the outer circumferentialsurface 17S of the tire case 17 through the roughening treatment. Oncethe vulcanization is completed, an anchor effect is exerted by thecushion rubber 29 that has flowed into the roughening irregularities,and the bonding strength between the tire case 17 and the cushion rubber29 is enhanced.

In the tire 200 produced by the method for producing a tire, the bondingstrength between the tire case 17 and the cushion rubber 29 is ensured.That is, the bonding strength between the tire case 17 and the tread 30is ensured due to the presence of the cushion rubber 29. Therefore,separation between the outer circumferential surface 17S of the tirecase 17 and the cushion rubber 29 in the tire 200 is suppressed.

Since the outer circumferential portion of the tire case 17 is formed ofthe reinforcing cord layer 28, puncture resistance and cuttingresistance are improved, compared with a case in which the outercircumferential portion is formed of a member other than the reinforcingcord layer 28.

Since the coated cord member 26B is wound to form the reinforcing cordlayer 28, the rigidity in the circumferential direction of the tire 200is improved. Since the rigidity in the circumferential direction isimproved, creeping of the tire case 17 (a phenomenon in which theplastic deformation of the tire case 17 increases with lapse of timeunder a constant stress) is suppressed, and pressure resistance to airpressure applied from the inner side in the tire radial direction isimproved.

Although irregularities are formed on the outer circumferential surface17S of the tire case 17 in the present embodiment, the second aspect ofthe invention is not limited to this configuration, and a configurationin which the outer circumferential surface 17S is formed flat may beadopted.

In the tire case 17, a reinforcing cord layer may be formed by covering,with a coating thermoplastic material, the coated cord member that hasbeen wound on the crown portion of the tire case and bonded thereto. Inthis case, the coating layer can be formed by ejecting the coatingthermoplastic material in the melted or softened state onto thereinforcing cord layer 28. The coating layer may be formed without usingan extruder, by heating a welding sheet into a melted or softened state,and attaching the welding sheet to the surface (the outercircumferential surface) of the reinforcing cord layer 28.

Although case divided parts (tire case half parts 17A) are bonded toform the tire case 17 in Embodiment 2-2, the second aspect of theinvention is not limited to this configuration, and the tire case 17 maybe formed as an integrated body using, for example, a mold.

The tire 200 according to Embodiment 2-2 is a so-called tubeless tire inwhich an air chamber is formed between the tire 200 and the rim 20 byfitting the bead portion 12 to the rim 20. However, the second aspect ofthe invention is not limited to this configuration, and the tire 200 mayhave, for example, a complete tube shape.

Although the cushion rubber 29 is interposed between the tire case 17and the tread 30 in Embodiment 2-2, the second aspect of the inventionis not limited to this configuration, and a configuration in which thecushion rubber 29 is not provided may be adopted.

Although a configuration in which the coated cord member 26B ishelically wound on the crown portion 16 is adopted in Embodiment 2-2,the second aspect of the invention is not limited to this configuration,and a configuration in which the coated cord member 26B is wound butdiscontinuous in the width direction may be adopted.

In Embodiment 2-2, a configuration is adopted in which a thermoplasticmaterial is used as the coating resin material 27 that forms the coatedcord member 26B, and in which the coating resin material 27 is melted orsoftened by heating, thereby welding the coated cord member 26B to theouter circumferential surface of the crown portion 16. However, thesecond aspect of the invention is not limited to this configuration, anda configuration in which the coated cord member 26B is adhered to theouter circumferential surface of the crown portion 16 using an adhesiveor the like, without heating the coating resin material 27, may beadopted.

A configuration may be adopted in which the coating resin material 27that forms the coated cord member 26B is a thermosetting resin, and inwhich the coated cord member 26B is adhered to the outer circumferentialsurface of the crown portion 16 using an adhesive or the like, withoutheating the coated cord member 26B.

A configuration may be adopted in which the coating resin material 27that forms the coated cord member 26B is a thermosetting resin, and inwhich the tire case 17 is formed of a thermoplastic resin material. Inthis case, the coated cord member 26B may be adhered to the outercircumferential surface of the crown portion 16 using an adhesive or thelike, or the coated cord member 26B may be welded to the outercircumferential surface of the crown portion 16 by heating a portion ofthe tire case 17 at which the coated cord member 26B is to be disposedto get into a melted or softened state.

A configuration may be adopted in which the coating resin material 27that forms the coated cord member 26B is a thermoplastic material, andin which the tire case 17 is formed of a thermoplastic resin material.In this case, the coated cord member 26B may be adhered to the outercircumferential surface of the crown portion 16 using an adhesive or thelike, or the coated cord member 26B may be welded to the outercircumferential surface of the crown portion 16 by heating a portion ofthe tire case 17 at which the coated cord member 26B is to be disposedto get into a melted or softened state as well as heating the coatingresin material 27 to get into a melted or softened state. In a case inwhich both the tire case 17 and the coated cord member 26B are heated toget into a melted or softened state, both materials mix with each otherwell, thereby increasing the bonding strength. In a case in which eachof the resin material that forms the tire case 17 and the coating resinmaterial 27 that forms the coated cord member 26B is a thermoplasticmaterial, the thermoplastic materials thereof are preferablythermoplastic materials of the same kind, and particularly the samethermoplastic material.

The outer circumferential surface 17S of the tire case 17 that has beensubjected to the roughening treatment may be subjected to coronatreatment, plasma treatment or the like so as to activate the outercircumferential surface 17S and so as to enhance the hydrophilicity, andan adhesive may thereafter be applied thereto.

The sequence employed in the production of the tire 200 is not limitedto the sequence specified in Embodiment 2-2, and may be modified, asappropriate.

Although modes for carrying out the second aspect of the invention aredescribed above with reference to embodiments, the embodiments aremerely examples, and may be practiced with various modifications withina range that does not depart from the gist of the second aspect. Ofcourse, the protection scope of the second aspect of the invention isnot limited to these embodiments.

Although specific modes of the second aspect of the invention aredescribed above with reference to Embodiment 2-1 and Embodiment 2-2, thesecond aspect of the invention is not limited to the modes describedabove.

<<Third Aspect of Invention>>

Next, a thermoplastic resin material that constitutes a tire frame inthe third aspect of the invention will be described first, and specificembodiments of a tire according to the third aspect of the inventionwill then be described with reference to the drawings.

[Thermoplastic Resin Material]

The tire according to the third aspect of the invention includes ancircular tire frame formed of a thermoplastic resin material thatincludes a polyamide-based thermoplastic elastomer and an acid-modifiedelastomer obtained by acid-modifying a thermoplastic elastomer otherthan the polyamide-based thermoplastic elastomer or a mixture of athermoplastic elastomer other than the polyamide-based thermoplasticelastomer and an acid-modified elastomer obtained by acid-modifying theother elastomer.

As described above, the thermoplastic resin material includes atleast 1) a combination of a polyamide-based thermoplastic elastomer andan acid-modified elastomer obtained by acid-modifying a thermoplasticelastomer other than polyamide-based thermoplastic elastomer or 2) acombination of a polyamide-based thermoplastic elastomer, athermoplastic elastomer other than polyamide-based thermoplasticelastomer, and an acid-modified elastomer obtained by acid-modifying athermoplastic elastomer other than polyamide-based thermoplasticelastomer.

The polyamide-based thermoplastic elastomer, the thermoplastic elastomer(other thermoplastic elastomer) other than polyamide-based thermoplasticelastomer, and the acid-modified elastomer obtained by acid-modifyingthe thermoplastic elastomer other than polyamide-based thermoplasticelastomer will be described below.

The “thermoplastic elastomer” and the “polyamide-based thermoplasticelastomer” are the same as in the first aspect of the invention.

The “thermoplastic elastomer other than polyamide-based thermoplasticelastomer” (other thermoplastic elastomer) means a thermoplasticelastomer that does not have an amide bond (—CONH—) in the main chain ofa polymer constituting a hard segment among thermoplastic elastomers.The scope of the “thermoplastic elastomer other than polyamide-basedthermoplastic elastomer” (other thermoplastic elastomer) does notinclude the below-described acid-modified elastomer obtained byacid-modifying the other thermoplastic elastomer.

Examples of the other thermoplastic elastomer include a polyolefin-basedthermoplastic elastomer and a polystyrene-based thermoplastic elastomer.

The polyolefin-based thermoplastic elastomer refers to an elastomer inwhich the polymer forming the hard segment is polyolefin, and thepolystyrene-based thermoplastic elastomer refer to an elastomer in whichthe polymer forming the hard segment is polystyrene.

More specifically, examples of the polyolefin-based thermoplasticelastomer (non-modified olefin-based thermoplastic elastomer) include Aseries, such as TAFMER A1050S and A4050S, manufactured by MitsuiChemicals Inc.

Examples of the polystyrene-based thermoplastic elastomer (non-modifiedstyrene-based thermoplastic elastomer) include H series, such as TUFTECH1221 and H1052, manufactured by Asahi Kasei Corporation, and G1641H andG1643N manufactured by Kraton Polymers LLC.

“Acid-modifying a thermoplastic elastomer other than polyamide-basedthermoplastic elastomer” means that an unsaturated compound having anacid group such as a carboxylic group, a sulfate group, or a phosphategroup is bonded to the other thermoplastic elastomer. For example, inthe case of using an unsaturated carboxylic acid (generally maleicanhydride) as the unsaturated compound having an acid group, anunsaturated bond site of an unsaturated carboxylic acid may be bonded toan olefin-based thermoplastic elastomer (by, for example, graftpolymerization).

The compound having an acid group is preferably a compound having acarboxylic group which is a weak acid group, from the viewpoint ofsuppression of deterioration of the polyamide-based thermoplasticelastomer and the thermoplastic elastomer other than polyamide-basedthermoplastic elastomer, and examples thereof include acrylic acid,methacrylic acid, itaconic acid, crotonic acid, isocrotonic acid, andmaleic acid.

Examples of the acid-modified olefin-based thermoplastic elastomerinclude TAFMER MA8510, MH7007, MH7010, MH7020, MP0610, MP0620, etc.manufactured by Mitsui Chemicals Inc.

Examples of the acid-modified styrene-based thermoplastic elastomerinclude TUFTEC products such as M1943, M1911, and M1913 manufactured byAsahi Kasei Corporation, and FG19181G manufactured by Kraton PolymersLLC.

The other thermoplastic elastomer and the acid-modified elastomer arepreferably hydrogenated so as to suppress an undesired cross-linkingreaction in the thermoplastic resin material. Examples of the otherthermoplastic elastomer and the acid-modified elastomer that arehydrogenated (SEBS) include TUFTEC products manufactured by Asahi KaseiCorporation.

In the third aspect of the invention, the thermoplastic resin materialmay be any thermoplastic resin material that includes an acid-modifiedelastomer obtained by acid-modifying the other thermoplastic elastomer,and the acid value of the thermoplastic resin material is greater than 0mg-CH₃ONa/g.

Here, the “acid value of the thermoplastic resin material” refers to thetotal mass of sodium methoxide (CH₃ONa) necessary for neutralization ofthe acid-modified sites of the acid-modified elastomer relative to thetotal mass of the thermoplastic resin material, and is calculated fromExpression (1) when only one acid-modified elastomer is included in thethermoplastic resin material, and is calculated from Expression (2) whentwo or more acid-modified elastomers are included in the thermoplasticresin material.

[(acid value of acid-modified elastomer A)×(total mass of acid-modifiedelastomer A)]/[total mass of thermoplastic resin material]  Expression(1)

[(acid value of acid-modified elastomer A)×(total mass of acid-modifiedelastomer A)+(acid value of acid-modified elastomer B)×(total mass ofacid-modified elastomer B)+ . . . ]/[total mass of thermoplastic resinmaterial]  Expression (2)

The acid value of acid-modified elastomer A in Expression (1) and theacid values of acid-modified elastomers A, B, . . . in Expression (2)are each measured as the mass [mg] of sodium methoxide (CH₃ONa) consumedin neutralizing titration using sodium methoxide (CH₃ONa) with respectto 1 [g] of each acid-modified elastomer.

In the description below, the unit of the acid value of eachacid-modified elastomer is also expressed as [mg(CH₃ONa)/g].

From the viewpoint of injection moldability of the thermoplastic resinmaterial, the acid value of the thermoplastic resin material ispreferably equal to or greater than 0.1 mg-CH₃ONa/g but less than 2.2mg-CH₃ONa/g, more preferably from 0.1 mg-CH₃ONa/g to 2.0 mg-CH₃ONa/g,and still more preferably from 0.1 mg-CH₃ONa/g to 1.5 mg-CH₃ONa/g.

The acid value of the thermoplastic resin material may be controlled bycontrolling the acid value of the acid-modified elastomer, or bycontrolling the mixing ratio of the other thermoplastic elastomer andthe acid-modified elastomer contained in the thermoplastic resinmaterial.

The thermoplastic resin material has a sea-island structure including asea phase which is a matrix phase formed of the polyamide-basedthermoplastic elastomer and an island phase which is a disperse phaseformed of the acid-modified elastomer and the other (unmodified)thermoplastic elastomer. In a case in which the interaction at the phaseinterface between the sea phase and the island phase is weak, thefluidity of the thermoplastic resin material increases, and excellentinjection moldability is exhibited. Since the acid-modified elastomerhas an acid-modified site in a molecule, its interaction with thepolyamide-based thermoplastic elastomer is stronger as compared with anelastomer that is not acid-modified.

In the sea-island structure, there is a tendency that an increase in theacid value decreases the island phase while a decrease in the acid valueenlarges the island phase. An acid value of the acid-modified elastomerwithin the range described above causes the island phase to be finelydispersed in the thermoplastic resin, thereby remarkably improving theimpact resistance of the thermoplastic resin material; further, the meltviscosity of the thermoplastic resin material does not increaseexcessively, and the injection moldability of the thermoplastic resinmaterial is excellent. Therefore, in the case of forming a tire caseusing the thermoplastic resin material, the thermoplastic resin needsnot be heated to high temperatures, and, therefore, damage to thethermoplastic resin material caused by excessive heating can be reduced.

The island phase of the acid-modified elastomer being finely dispersedin the thermoplastic resin can be confirmed by photographic observationusing a SEM (Scanning Electron Microscope).

The acid value of the acid-modified elastomer is preferably higher than0 mg(CH₃ONa)/g but equal to or less than 20 mg(CH₃ONa)/g, morepreferably higher than 0 mg(CH₃ONa)/g but equal to or less than 17mg(CH₃ONa)/g, and still more preferably higher than 0 mg(CH₃ONa)/g butequal to or less than 15 mg(CH₃ONa)/g.

Regarding the acid value of the acid-modified elastomer, in a case inwhich one acid-modified elastomer is contained in the thermoplasticresin material, the acid value of the acid-modified elastomer ispreferably in the range described above; in a case in which two or moreacid-modified elastomers are contained in the thermoplastic resinmaterial, the acid value of each acid-modified elastomer is preferablyin the range described above.

The ratio (the mass of the polyamide-based thermoplastic elastomer:thetotal mass of the other thermoplastic elastomer and the acid-modifiedelastomer) of the mass of the polyamide-based thermoplastic elastomerand the total mass of the other thermoplastic elastomer and theacid-modified elastomer in the thermoplastic resin material ispreferably from 95:5 to 55:45, from the viewpoint of allowing thepolyamide-based thermoplastic elastomer to form the sea phase. The ratiois more preferably 90:10 to 60:40.

The content of the polyamide-based thermoplastic elastomer in thethermoplastic resin material in the third aspect of the invention is notparticularly limited, but is preferably 55 mass % to 95 mass % and morepreferably 60 mass % to 90 mass %, with respect to the total mass of thethermoplastic resin material. When the content of the polyamide-basedthermoplastic elastomer is 55 mass % to 95 mass % with respect to thetotal mass of the thermoplastic resin material, the characteristics ofthe thermoplastic resin material can sufficiently be exerted, and thetensile modulus of elasticity and the fracture properties of the tirecan be improved.

The thermoplastic resin material may contain, if desired, variousfillers (such as silica, calcium carbonate, and clay) and variousadditives such as an anti-aging agent, oils, plasticizers, colorants,weather-resistant agents, and reinforcing agents.

The thermoplastic resin material can be obtained by compounding thepolyamide-based thermoplastic elastomer and the acid-modified elastomer(and, further, the other thermoplastic elastomer in a case in which thethermoplastic resin material contains the other thermoplasticelastomer), adding, if necessary, various additives, and carrying outmelt-mixing. The mixing ratio of the polyamide-based thermoplasticelastomer, the acid-modified elastomer, and the other thermoplasticelastomer may be the ratio as described above. The resin obtained bymelt- and mixing may be used after shaped into a pellet, if necessary.

In the third aspect of the invention, the tensile modulus of elasticityas defined in JIS K7113:1995 of the thermoplastic resin material ispreferably 100 MPa to 1000 MPa, more preferably 100 MPa to 800 MPa, andparticularly preferably 100 MPa to 700 MPa. When the tensile modulus ofelasticity of the thermoplastic resin material is 100 MPa to 1000 MPa,fitting to a rim can be efficiently carried out while maintaining theshape of the tire frame.

In the third aspect of the invention, the tensile strength at yield asdefined in JIS K7113:1995 of the thermoplastic resin material ispreferably equal to or greater than 5 MPa, more preferably 5 MPa to 20MPa, and still more preferably 5 MPa to 17 MPa. When the tensilestrength at yield of the thermoplastic resin material is equal to orgreater than 5 MPa, deformation due to a load applied to the tire at thetime of traveling or the like can be tolerated.

In the third aspect of the invention, the tensile elongation at yield asdefined in JIS K7113:1995 of the thermoplastic resin material ispreferably equal to or higher than 10%, more preferably 10% to 70%, andstill more preferably 15% to 60%. When the tensile elongation at yieldof the thermoplastic resin material is equal to or higher than 10%, theelastic region is large, and fittability to a rim can be improved.

In the third aspect of the invention, the tensile elongation at break asdefined in JIS K7113:1995 of the thermoplastic resin material ispreferably equal to or higher than 50%, more preferably equal to orhigher than 100%, still more preferably equal to or higher than 150%,and particularly preferably equal to or higher than 200%. When thetensile elongation at break of the thermoplastic resin material is equalto or higher than 50%, fittability to a rim is excellent, and resistanceto break at collision can be enhanced.

In the third aspect of the invention, the deflection temperature underload (under a load of 0.45 MPa) as defined in ISO 75-2 or ASTM D648 ofthe thermoplastic resin material is preferably equal to or higher than50° C., more preferably 50° C. to 150° C., and still more preferably 50°C. to 130° C. When the deflection temperature under load of thethermoplastic resin material is equal to or higher than 50° C.,deformation can be suppressed during a step of vulcanizing a tread orthe like.

[Resin Material as Component of Reinforcing Cord Layer]

The tire according to the third aspect of the invention may have areinforcing cord member which is wound on the outer circumference of thetire frame in the circumferential direction to form a reinforcing cordlayer.

The reinforcing cord layer may be configured to include a resinmaterial. When a resin material is included in the reinforcing cordlayer as described above, a difference in hardness between the tire andthe reinforcing cord layer can be decreased, and, therefore, thereinforcing cord member can be more tightly adhered and fixed to thetire frame, compared with a case in which the reinforcing cord member isfixed using a cushion rubber. The concept of “resin material”, such asthat described above, encompasses thermoplastic resins (includingthermoplastic elastomers) as well as thermosetting resins, but does notencompass vulcanized rubbers.

In a case in which the reinforcing cord member is a steel cord, and inwhich an attempt is made to separate the reinforcing cord member fromthe cushion rubber at the time of disposal of the tire, vulcanizedrubbers are difficult to separate from the reinforcing cord member onlyby heating; in contrast, resin materials can be separated from thereinforcing cord member only by heating, which is advantageous in termsof recyclability of the tire. Resin materials usually have a loss factor(tan δ) lower than that of vulcanized rubbers. Accordingly, when thereinforcing cord layer contains a large amount of resin material, therolling properties of the tire can be enhanced. Resin materials, havinga higher elastic modulus relative to vulcanized rubbers, areadvantageous in that the resin materials have high in-plane shearstiffness, and also provide excellent steering stability and excellentabrasion resistance at the time of traveling with the tire.

Examples of the thermosetting resin which may be used in the reinforcingcord layer include phenol resins, urea resins, melamine resins, epoxyresins, polyamide resins, polyester resins, etc.

Examples of the thermoplastic resin include urethane resins, olefinresins, vinyl chloride resins, polyamide resins, and polyester resins.

The thermoplastic elastomer and the elastic modulus (the tensile modulusof elasticity as defined in JIS K7113) of the resin material used in thereinforcing cord layer are the same as those described in [ResinMaterial as Component of Reinforcing Cord Layer] in the first aspect ofthe invention.

Embodiment 3-1

A tire according to Embodiment 3-1 of the tire according to the thirdaspect of the invention will be described below with reference to theaccompanying drawings.

The tire according to Embodiment 3-1 is the same as the tire accordingto Embodiment 1-1 described above, except for the points discussedbelow. Therefore, the same or corresponding drawings and members will bedescribed using the same reference characters and figures.

The tire case 17 according to the present embodiment is formed of athermoplastic resin material constituted by a mixed material of apolyamide-based thermoplastic elastomer (UBESTA XPA9055X1 manufacturedby Ube Industries, Ltd.) and an α-olefin-based thermoplastic elastomer(TAFMER MH7010 manufactured by Mitsui Chemicals Inc.), the thermoplasticresin material having an acid value of 1.11 mg-CH₃ONa/g.

The thermoplastic resin material according to the present embodimentincludes a polyamide-based thermoplastic elastomer and an acid-modifiedelastomer obtained by acid-modifying a thermoplastic elastomer otherthan polyamide-based thermoplastic elastomer. In particular, an acidvalue of the thermoplastic resin material of equal to or greater than0.1 mg-CH₃ONa/g but less than 2.2 mg-CH₃ONa/g results in excellentfluidity of the thermoplastic resin material, provides a melt viscositythat is not excessively high, and therefore provides excellent injectionmoldability.

The tire case 17 is not limited to a tire case formed by bonding twomembers, and may be formed by bonding three or more members. The otherdetails are the same as those of the tire according to Embodiment 1-1,and the production method therefor is also the same.

(Effects)

The tire 10 according to the present embodiment, since the tire case 17is formed of the thermoplastic resin material, the tire case 17 hasexcellent tensile modulus of elasticity and excellent fractureproperties, and, since the structure thereof can be simplified, the tirecase 17 has a smaller weight than conventional rubbers. Therefore, theapplication of the tire 10 according to the present embodiment to avehicle enables a decrease in the weight of the vehicle, and reducesfuel consumption.

In particular, when the acid value of the thermoplastic resin materialused to form the tire case 17 is equal to or greater than 0.1mg-CH₃ONa/g but less than 2.2 mg-CH₃ONa/g. the thermoplastic resinmaterial has a sea-island structure in which the polyamide-basedthermoplastic elastomer serves as a sea phase, and in which theacid-modified elastomer, or the acid-modified elastomer and the other(unmodified) thermoplastic elastomer serves as an island phase, and inwhich the island phase is finely dispersed in the thermoplastic resinmaterial; therefore, the impact resistance, tensile elasticity, andfracture properties of the tire 10 are improved.

The polyamide-based thermoplastic elastomer which is a constituentcomponent of the thermoplastic resin material has high adhesiveness tothe reinforcing cord 26, and has excellent fixing performance such aswelding strength. Therefore, a phenomenon (incorporation of air) inwhich air remains around the reinforcing cord 26 can be suppressed inthe reinforcing cord winding step. The high adhesiveness and weldabilityto the reinforcing cord 28 and suppression of incorporation of air intoa region around the reinforcing cord member effectively suppressesmovement of the reinforcing cord 26 at the time a force is appliedduring traveling. Accordingly, for example, even in a case in which tirecomponent members are disposed on the outer circumference of the tireframe so as to cover the entire reinforcing cord member, the movement ofthe reinforcing cord member is suppressed, whereby separation betweenthe members (including the tire frame), for example, is suppressed, andthe durability of the tire 10 is improved.

In the tire 10 according to the present embodiment, since thereinforcing cord 26 having rigidity higher than that of thethermoplastic resin material is helically wound on the outercircumferential surface of the crown portion 16 of the tire case 17formed of a thermoplastic resin material in the circumferentialdirection, puncture resistance, cutting resistance, and rigidity in thecircumferential direction of the tire 10 are improved. The improvedrigidity in the circumferential direction of the tire 10 preventscreeping of the tire case 17 formed of a thermoplastic resin material.

In a cross-sectional view taken along the axial direction of the tirecase 17 (the cross-section shown in FIG. 1), at least a part of thereinforcing cord 26 is embedded in the outer circumferential surface ofthe crown portion 16 of the tire case 17 formed of the thermoplasticresin material, and is in close contact with the thermoplastic resinmaterial, as a result of which incorporation of air during production issuppressed, and movement of the reinforcing cord 26 due to, for example,a force applied at the time of traveling is suppressed. Accordingly,separation between of the reinforcing cord 26, the tire case 17, and thetread 30 is suppressed, and the durability of the tire 10 is improved.

As shown in FIG. 2, since the depth L of embedding of the reinforcingcord 26 is set to be equal to or greater than ⅕ of the diameter Dthereof, it incorporation of air during production is effectivelysuppressed, and movement of the reinforcing cord 26 due to a forceapplied thereto at the time of traveling is further suppressed.

In a case in which the reinforcing cord layer 28 is configured toinclude the thermoplastic resin material as described above, thereinforcing cord 26 can be made to more tightly contact the tire case 17and fixed to the tire case 17 since the difference in hardness betweenthe tire case 17 and the reinforcing cord layer 28 can be made smallerthan that in a case in which the reinforcing cord 26 is fixed using acushion rubber. Accordingly, the incorporation of air mentioned abovecan effectively be prevented, and the movement of the reinforcing cordmember at the time of traveling can effectively be suppressed. In a casein which the reinforcing cord 26 is a steel cord, the reinforcing cord26 can easily be separated from the thermoplastic resin material byheating and recovered at the time of disposing of the tire, and,therefore, there is an advantage from the viewpoint of recyclability ofthe tire 10. Further, the resin material usually has a lower loss factor(tan δ) compared with vulcanized rubbers, inclusion of a large amount ofresin material in the reinforcing cord layer makes it possible toenhance the rolling properties of the tire. Resin materials, having ahigher elastic modulus relative to vulcanized rubbers, are advantageousin that the resin materials have high in-plane shear stiffness, and alsoprovide excellent steering stability and excellent abrasion resistanceat the time of traveling with the tire.

Since the tread 30 that contacts a road surface is formed of a rubbermaterial having higher abrasion resistance than that of thethermoplastic resin material, the abrasion resistance of the tire 10 isimproved.

Since the annular bead core 18 formed of a metal material is embedded inthe bead portion 12, the tire case 17 is strongly fixed to the rim 20,i.e., the tire 10 is strongly fixed to the rim 20, similarly toconventional rubber pneumatic tires.

Since the sealing layer 24 formed of a rubber material having highersealing ability than the thermoplastic resin material is disposed in aregion of the bead portion 12 that contacts the rim 20, sealing betweenthe tire 10 and the rim 20 is improved. Therefore, compared with a casein which sealing is carried out with the rim 20 and the thermoplasticresin material, air leakage from the tire is further suppressed.Further, provision of the sealing layer 24 also improves fittability tothe rim.

Although a configuration in which the reinforcing cord 26 is heated suchthat the thermoplastic resin material in a portion that contacts theheated reinforcing cord 26 is melted or softened is adopted in theembodiment described above, the third aspect of the invention is notlimited to this configuration; a hot air generating device may be used,instead of heating the reinforcing cord 26, to heat the outercircumferential surface of the crown portion 16 in which the reinforcingcord 26 is to be embedded, and the reinforcing cord 26 may thereafter beembedded in the crown portion 16.

Although the heat source of the cord heating device 59 includes theheater and the fan in Embodiment 3-1, the third aspect of the inventionis not limited to this configuration, and a configuration in which thereinforcing cord 26 is directly heated by radiation heat (for example,infrared rays) may be adopted.

Although a configuration in which a region at which the thermoplasticresin material with the reinforcing cord 26 embedded therein is meltedor softened is forcibly cooled with the second roller 64 formed of metalis adopted in Embodiment 3-1, the third aspect of the invention is notlimited to this configuration; a configuration in which cold air isdirectly applied to the region at which the thermoplastic resin materialis melted or softened, to forcibly cool and solidify the region at whichthe thermoplastic resin material is melted or softened may also beadopted.

Although a configuration in which the reinforcing cord 26 is heated isadopted in Embodiment 3-1, a configuration in which the outercircumference of the reinforcing cord 26 is coated with the samethermoplastic resin material as the tire case 17, for example, may beadopted. In this case, by heating the coated thermoplastic resinmaterial along with the reinforcing cord 26 when the coated reinforcingcord is wound on the crown portion 16 of the tire case 17, incorporationof air can effectively be suppressed at the time of embedding thereinforcing cord in the crown portion 16.

Helically winding the reinforcing cord 26 is easy from the viewpoint ofproduction. However, a method in which the reinforcing cord 26 isdiscontinuous in the width direction, for example, may also becontemplated.

The tire 10 according to Embodiment 3-1 is a so-called tubeless tire inwhich an air chamber is formed between the tire 10 and the rim 20 byfitting the bead portion 12 to the rim 20. However, the third aspect ofthe invention is not limited to this configuration, and a complete tubeshape may be adopted.

The complete tube-shaped tire may have a configuration in which, forexample, three tire frames each having an annular shape are arranged inthe tire width direction, as shown in FIG. 4. FIG. 4 is across-sectional view of a tire according to another embodiment. As shownin FIG. 4, a tire 86 includes a tread rubber layer 87, annular hollowtubes (tire frames) 88 formed of the same resin material as described inEmbodiment 3-1, a belt (reinforcing cord) 89, and a rim 90. Three tubes88 are arranged in the tire width direction of the tire 86. The treadrubber layer 87 in which the belt 89 is embedded is bonded to the outercircumferential portions of the tubes 88. The tubes 88 are fitted to therim 90 having recess portions that engage with the tubes 88. The tire 86is not provided with a bead core.

Although modes for carrying out the third aspect of the invention aredescribed above with reference to embodiments, the embodiments aremerely examples, and may be practiced with various modifications withina range that does not depart from the gist of the third aspect. Ofcourse, the protection scope of the third aspect of the invention is notlimited to these embodiments.

Embodiment 3-2

A method for producing a tire according to the third aspect of theinvention, and a tire according to Embodiment 3-2 will be describedbelow with reference to the drawings. Similarly to Embodiment 3-1, thetire according to the present embodiment has substantially the samecross-sectional shape as those of conventional general rubber pneumatictires.

The tire according to Embodiment 3-2 is the same as the tire accordingto Embodiment 1-2 described above, except for the points discussedbelow. Therefore, the same or corresponding drawings and members will bedescribed using the same reference characters and figures.

Similarly to Embodiment 3-1, the tire case 17 according to Embodiment3-2 is formed of a mixed material of a polyamide-based thermoplasticelastomer (UBESTA XPA9055X1 manufactured by Ube Industries, Ltd.) and anα-olefin-based thermoplastic elastomer (TAFMER MH7010″ manufactured byMitsui Chemicals Inc.), the thermoplastic resin material having an acidvalue of 1.11 mg-CH₃ONa/g. The other details are the same as those ofthe tire according to Embodiment 1-2, and the production method thereforis also the same.

In the present embodiment, the same material (the mixed material (whichis a thermoplastic resin material having an acid value of 1.11mg-CH₃ONa/g) of UBESTA XPA9055X1 manufactured by Ube Industries, Ltd.and TAFMER MH7010 manufactured by Mitsui Chemicals Inc.) is used as acoating resin material 27 in the present embodiment.

(Effects)

The tire 200 according to the present embodiment has excellent heatresistance, excellent tensile modulus of elasticity, excellent tensilestrength, and excellent fracture strain since the tire case 17 is formedof the thermoplastic resin material. In addition, since the structurethereof can be simplified, the weight thereof is smaller than those ofconventional rubber tires. Therefore, the tire 200 according to thepresent embodiment has high abrasion resistance and high durability.

In a case in which the reinforcing cord layer 28 is configured toinclude the coated cord member 26B, the coated cord member 26B can bemade to more tightly contact the tire case 17 and fixed to the tire case17 since the difference in hardness between the tire case 17 and thereinforcing cord layer 28 can be made smaller than that in a case inwhich the reinforcing cord 26A is fixed using only the cushion rubber29. Accordingly, the incorporation of air mentioned above caneffectively be prevented, and the movement of the reinforcing cordmember at the time of traveling can effectively be suppressed. In a casein which the reinforcing cord is a steel cord, the cord member 26A caneasily be separated and from the coated cord member 26B by heating andrecovered at the time of disposing of the tire, and, therefore, there isan advantage from the viewpoint of recyclability of the tire 200. Sinceresin materials usually have a lower loss factor (tan δ) than that ofvulcanized rubbers, inclusion of a large amount of resin material in thereinforcing cord layer makes it possible to enhance the rollingproperties of the tire. Resin materials, having a higher elastic modulusrelative to vulcanized rubbers, are advantageous in that the resinmaterials have high in-plane shear stiffness, and also provide excellentsteering stability and abrasion resistance at the time of traveling withthe tire.

In the method for producing a tire according to the present embodiment,when the tire case 17, the cushion rubber 29, and the tread rubber 30Aare integrated, the bonding properties (adhesion properties) is improvedby the anchor effect since the outer circumferential surface 17S of thetire case 17 has been subjected to the roughening treatment. Further,since the resin material forming the tire case 17 is ploughed due tocollision of the blasting abrasive, the wettability of the adhesive isimproved. Therefore, the bonding agent is retained, in a uniformlyapplied state, on the outer circumferential surface 17S of the tire case17, whereby the bonding strength between the tire case 17 and thecushion rubber 29 can be ensured.

In particular, even in a case in which irregularities are formed on theouter circumferential surface 17S of the tire case 17, a portionsurrounding a recess (walls at the recess, the bottom of the recess) isroughened by allowing the blasting abrasive to collide with the portionssurrounding the recess (the gap 28A), whereby the bonding strengthbetween the tire case 17 and the cushion rubber 29 can be enhanced.

Since the cushion rubber 29 is superposed on the roughened area of theouter circumferential surface 17S of the tire case 17, the bondingstrength between the tire case 17 and the cushion rubber can effectivelybe ensured.

In the case of vulcanization of the cushion rubber 29 in thevulcanization step, the cushion rubber 29 flows into the rougheningirregularities that have been formed on the outer circumferentialsurface 17S of the tire case 17 through the roughening treatment. Oncethe vulcanization is completed, an anchor effect is exerted by thecushion rubber 29 that has flowed into the roughening irregularities,and the bonding strength between the tire case 17 and the cushion rubber29 is enhanced.

In the tire 200 produced by the method for producing a tire, the bondingstrength between the tire case 17 and the cushion rubber 29 is ensured.That is, the bonding strength between the tire case 17 and the tread 30is ensured due to the presence of the cushion rubber 29. Therefore,separation between the outer circumferential surface 17S of the tirecase 17 and the cushion rubber 29 in the tire 200 is suppressed at thetime of, for example, traveling.

Since the outer circumferential portion of the tire case 17 is formed ofthe reinforcing cord layer 28, puncture resistance and cuttingresistance are improved, compared with a case in which the outercircumferential portion is formed of a member other than the reinforcingcord layer 28.

Since the coated cord member 26B is wound to form the reinforcing cordlayer 28, the rigidity in the circumferential direction of the tire 200is improved. Since the rigidity in the circumferential direction isimproved, creeping of the tire case 17 (a phenomenon in which theplastic deformation of the tire case 17 increases with lapse of timeunder a constant stress) is suppressed, and pressure resistance to airpressure applied from the inner side in the tire radial direction isimproved.

Although irregularities are formed on the outer circumferential surface17S of the tire case 17 in the present embodiment, the third aspect ofthe invention is not limited to this configuration, and a configurationin which the outer circumferential surface 17S is formed flat may beadopted.

In the tire case 17, a reinforcing cord layer may be formed by covering,with a coating thermoplastic material, the coated cord member that hasbeen wound on the crown portion of the tire case and bonded thereto. Inthis case, the coating layer can be formed by ejecting the coatingthermoplastic material in the melted or softened state onto thereinforcing cord layer 28. The coating layer may be formed without usingan extruder, by heating a welding sheet into a melted or softened state,and attaching the welding sheet to the surface (the outercircumferential surface) of the reinforcing cord layer 28.

Although case divided parts 17A are bonded to form the tire case 17 inEmbodiment 3-2, the third aspect of the invention is not limited to thisconfiguration, and the tire case 17 may be formed as an integrated bodyusing, for example, a mold.

The tire 200 according to Embodiment 3-2 is a so-called tubeless tire inwhich an air chamber is formed between the tire 200 and the rim 20 byfitting the bead portion 12 to the rim 20. However, the third aspect ofthe invention is not limited to this configuration, and the tire 200 mayhave, for example, a complete tube shape (for example, the shape shownin FIG. 4).

Although the cushion rubber 29 is interposed between the tire case 17and the tread 30 in Embodiment 3-2, the third aspect of the invention isnot limited to this configuration, and a configuration in which thecushion rubber 29 is not provided may be adopted.

Although a configuration in which the coated cord member 26B ishelically wound on the crown portion 16 is adopted in Embodiment 3-2,the third aspect of the invention is not limited to this configuration,and a configuration in which the coated cord member 26B is wound butdiscontinuous in the width direction may be adopted.

In Embodiment 3-2, a configuration is adopted in which a thermoplasticmaterial is used as the coating resin material 27 that forms the coatedcord member 26B, and in which the coating resin material 27 is melted orsoftened by heating, thereby welding the coated cord member 26B to theouter circumferential surface of the crown portion 16. However, thethird aspect of the invention is not limited to this configuration, anda configuration in which the coated cord member 26B is adhered to theouter circumferential surface of the crown portion 16 using an adhesiveor the like, without heating the coating resin material 27, may beadopted.

A configuration may be adopted in which the coating resin material 27forming the coated cord member 26B is a thermosetting resin, and inwhich the coated cord member 26B is adhered to the outer circumferentialsurface of the crown portion 16 using an adhesive or the like, withoutheating the coated cord member 26B.

A configuration may be adopted in which the coating resin material 27that forms the coated cord member 26B is a thermosetting resin, and inwhich the tire case 17 is formed of a thermoplastic resin material. Inthis case, the coated cord member 26B may be adhered to the outercircumferential surface of the crown portion 16 using an adhesive or thelike, or the coated cord member 26B may be welded to the outercircumferential surface of the crown portion 16 by heating a portion ofthe tire case 17 at which the coated cord member 26B is to be disposedto get into a melted or softened state.

A configuration may be adopted in which the coating resin material 27that forms the coated cord member 26B is a thermoplastic material, andin which the tire case 17 is formed of a thermoplastic resin material.In this case, the coated cord member 26B may be adhered to the outercircumferential surface of the crown portion 16 using an adhesive or thelike, or the coated cord member 26B may be welded to the outercircumferential surface of the crown portion 16 by heating a portion ofthe tire case 17 at which the coated cord member 26B is to be disposedto get into a melted or softened state as well as heating the coatingresin material 27 to get into a melted or softened state.

In a case in which both the tire case 17 and the coated cord member 26Bare heated to get into a melted or softened state, both materials mixwith each other well, thereby increasing the bonding strength. In a casein which each of the resin material that forms the tire case 17 and thecoating resin material 27 that forms the coated cord member 26B is athermoplastic resin material, the thermoplastic materials thereof arepreferably thermoplastic materials of the same kind, and particularlypreferably the same thermoplastic material.

The outer circumferential surface 17S of the tire case 17 that has beensubjected to the roughening treatment may be subjected to coronatreatment, plasma treatment or the like so as to activate the outercircumferential surface 17S and so as to enhance the hydrophilicity, andan adhesive may thereafter be applied thereto.

The sequence employed in the production of the tire 200 is not limitedto the sequence described in Embodiment 3-2, and may be modified, asappropriate.

Although modes for carrying out the third aspect of the invention aredescribed above with reference to embodiments, the embodiments aremerely examples, and may be practiced with various modifications withina range that does not depart from the gist of the third aspect. Ofcourse, the protection scope of the third aspect of the invention is notlimited to these embodiments.

Although specific modes of the third aspect of the invention aredescribed above with reference to Embodiment 3-1 and Embodiment 3-2, thethird aspect of the invention is not limited to the modes describedabove.

<<Fourth Aspect of the Invention>>

A tire of the fourth aspect of the invention includes a circular tireframe formed of a thermoplastic resin material, and the thermoplasticresin material includes a thermoplastic elastomer including a hardsegment and a soft segment in a molecule thereof, and specificneedle-shaped crystal grains.

Due to the above described configuration, the tire of the fourth aspectof the invention exhibits high elastic modulus and small rollingresistance.

Here, the “elastic modulus” means a tensile modulus of elasticitydefined in JIS K7113:1995, as long as it is not specified differently.

The rolling resistance of the tire of the fourth aspect of the inventioncan be expressed using tan δ, which is exhibited by the thermoplasticresin material forming the tire, as an index. The loss factor (tan δ) ofthe thermoplastic resin material is considered to correspond to themagnitude of strain generated in the thermoplastic resin material when astress is applied to the thermoplastic resin material. Therefore, thelarger tan δ of the thermoplastic resin material forming the tire framemeans that stain can be more easily generated in the tire when a stressis applied to the tire due to friction between the tire and a roadsurface at the time of traveling of a vehicle. As the tire generateslarger strain, the rolling resistance of the tire becomes larger.

In this description, the “loss factor (tan δ)” is a value calculated bya ratio (G″/G′) between the storage shear elastic modulus (G′) and theloss shear elastic modulus (G″) at 30° C., 20 Hz, and 1% of shearingstrain, and is a value representing a degree to which a material absorbsenergy (converts into heat) when the material is deformed (hereinafter,also referred to as “tan δ”). Since the larger tan δ causes absorptionof more energy, the rolling resistance of the tire increases andconsequently serves as a reason of degradation in fuel efficiency of thetire. The tan δ of the thermoplastic elastomer can be measured by theuse of a dynamic viscoelasticity measuring apparatus (Dynamic-MechanicalAnalysis: DMA).

The tire frame or the like which is a constituent element of the tire ofthe fourth aspect of the invention, will be described below and thenspecific embodiments of the tire of the fourth aspect of the invention,will be then described with reference to the accompanying drawings.

[Tire Frame]

The tire frame in the fourth aspect of the invention is formed of athermoplastic resin material including a thermoplastic elastomerincluding a hard segment and a soft segment in a molecule, and specificneedle-shaped crystal grains.

(Thermoplastic Resin Material)

The thermoplastic resin material in the fourth aspect of the inventionincludes at least the thermoplastic elastomer and specific needle-shapedcrystal grains and may include other components optionally.

Here, the “thermoplastic resin material” in the fourth aspect of theinvention means a material including at least a thermoplastic elastomerand specific needle-shaped crystal grains, and a material includingother components in addition to these components also belongs to thethermoplastic resin material.

The “thermoplastic elastomer” in the fourth aspect of the inventionmeans a thermoplastic resin formed of a copolymer having a polymerconstituting a crystalline hard segment with a high melting point or ahard segment with a high cohesive force and a polymer constituting anon-crystalline soft segment with a low glass transition temperature ina molecule thereof.

The “thermoplastic resin” in the fourth aspect of the invention does notencompass a vulcanized rubber such as conventional natural rubber,synthetic rubber, or the like.

In general, a thermoplastic elastomer having a high elastic modulus hasoften a high loss factor (tan δ) and it is thus difficult to form a tireframe with high elasticity and small tan δ.

By forming the tire frame of the tire of the invention according to thefourth aspect with the thermoplastic resin material including thethermoplastic elastomer, and needle-shaped crystal grains, it ispossible to achieve high elastic modulus while keeping tan δ low.Accordingly, it is possible to provide a tire with small rollingresistance and with a high elastic modulus.

<Needle-Shaped Crystal Grains with Fiber Length of 1 μm to 500 μm andwith Fiber Diameter of 0.01 μm to 10.0 μm>

The thermoplastic resin material in the fourth aspect of the inventionincludes needle-shaped crystal grains (specific needle-shaped crystalgrains) with a fiber length of 1 μm to 500 μm and which a fiber diameterof 0.01 μm to 10.0 μm, as well as a thermoplastic elastomer.

The average fiber length (L) of the specific needle-shaped crystalgrains is from 1 μm to 500 μm, preferably from 5 μm to 100 μm, and morepreferably from 10 μm to 30 μm.

The average fiber diameter (D) of the specific needle-shaped crystalgrains is from 0.01 μm to 10.0 μm, preferably from 0.1 μm to 5 μm, andmore preferably from 0.5 μm to 1.0 μm.

The aspect ratio (L/D) of the specific needle-shaped crystal grains isfrom 1 to 50000, preferably from 10 to 1000, and more preferably from 20to 500.

The average fiber length (L) and the average fiber diameter (D) of thespecific needle-shaped crystal grains are values statistically obtainedfrom electron microscope images of sampled particles.

The aspect ratio (L/D) of the specific needle-shaped crystal grains iscalculated by dividing the average fiber length (L) by the average fiberdiameter (D).

A reinforcing material such as carbon black widely used in the relatedart as a reinforcing material such as a rubber forming the tire frameenhances the elastic modulus of the tire frame, but also raises tan δwhen a stress is applied to the tire. On the contrary, the specificneedle-shaped crystal grains in the fourth aspect of the invention cansuppress the increase of tan δ while enhancing the elastic modulus ofthe tire frame.

The specific needle-shaped crystal grains in the fourth aspect of theinvention may be organic particles or inorganic particles, butpreferably inorganic particles from the viewpoint of enhancement of theelastic modulus. The specific needle-shaped crystal grains which areinorganic particles include needle-shaped monocrystalline particlesknown as whiskers.

Examples of organic particles which can be used as the specificneedle-shaped crystal grains include organic particles containing apolysaccharide material such as cellulose or a lipid material such astriacyl glycerol.

It is preferable that inorganic particles which can be used as thespecific needle-shaped crystal grains be selected from metal oxide,metal nitride, metal carbonate, metal silicate, metal titanate, metalsulfate, or metal borate.

Examples of the metal oxide which can be used as the specificneedle-shaped crystal grains include silica, alumina, titanium oxide,zinc oxide, magnesium oxide, manganese oxide, lithium oxide, zirconiaoxide, and tin oxide.

Examples of the metal nitride which can be used as the specificneedle-shaped crystal grains include potassium nitride, sodium nitride,gallium nitride, titanium nitride, and lithium nitride.

Examples of the metal carbonate which can be used as the specificneedle-shaped crystal grains include calcium carbonate, magnesiumcarbonate, lithium carbonate, potassium carbonate, strontium carbonate,and barium carbonate.

Examples of the metal silicate which can be used as the specificneedle-shaped crystal grains include calcium silicate, potassiumsilicate, magnesium silicate, and aluminum silicate.

Examples of the metal titanate which can be used as the specificneedle-shaped crystal grains include potassium titanate, sodiumtitanate, and barium titanate.

Examples of the metal sulfate which can be used as the specificneedle-shaped crystal grains include sodium sulfate, calcium sulfate,potassium sulfate, magnesium sulfate, and zinc sulfate.

Examples of the metal borate which can be used as the specificneedle-shaped crystal grains include sodium borate, calcium borate,magnesium borate, and aluminum borate.

Among these inorganic particles, inorganic particles selected from metalsulfate, metal borate, or metal titanate can be preferably used from theviewpoint of enhancement in elastic modulus and maintenance of low tanδ, and inorganic particles of metal sulfate can be more preferably used.

A preferable example of the metal sulfate which can be used as thespecific needle-shaped crystal grains is magnesium sulfate, andneedle-shaped crystal grains of magnesium sulfate expressed byMgSO₄.5Mg(OH)₂.3H₂O can be used. When large shearing energy is appliedthereto by kneading at the time of preparing the thermoplastic resinmaterial forming the tire frame, the needle-shaped crystal grains ofmagnesium sulfate are decomposed into finer crystal grains and finelyand uniformly dispersed in a thermoplastic resin material, whereby it ispossible to further enhance the elastic modulus and to maintain low tanδ.

A commercially-available products may be used as the specificneedle-shaped crystal grains which are inorganic particles, and examplesthereof include “MOS-HIGE” manufactured by Ube Material Industries Ltd.,“WHISTATT” manufactured by Otsuka Chemical Co., Ltd., and “AROREX”manufactured by Shikoku Chemicals Corporation.

The specific needle-shaped crystal grains contained in the thermoplasticresin material may be of one kind or of two or more kinds.

The content of the specific needle-shaped crystal grains with respect tothe total mass of the thermoplastic resin material is preferably from0.1 to 10 mass %, more preferably from 0.1 to 5 mass %, and still morepreferably from 0.1 to 1 mass %.

<Thermoplastic Elastomer>

The thermoplastic resin material in the fourth aspect of the inventionincludes a thermoplastic elastomer.

Examples of the thermoplastic elastomer which can be used in the fourthaspect of the invention include a polyamide-based thermoplasticelastomer (TPA), a polyester-based thermoplastic elastomer (TPC), apolyolefin-based thermoplastic elastomer (TPO), a polystyrene-basedthermoplastic elastomer (TPS), a polyurethane-based thermoplasticelastomer (TPU), a thermoplastic cross-linked rubber (TPV), and otherthermoplastic elastomers (TPZ), which are defined in JIS K6418:2007.

—Polyamide-Based Thermoplastic Elastomer—

Here, as the “polyamide-based thermoplastic elastomer”, the samepolyamide-based thermoplastic elastomer as described in the first aspectof the invention, may be used.

—Polyester-Based Thermoplastic Elastomer—

Examples of the polyester-based thermoplastic elastomer includematerials in which at least polyester constitutes a crystalline hardsegment with a high melting point and another polymer (such as polyesterand polyether) constitutes a non-crystalline soft segment with a lowglass transition temperature. The “polyester-based thermoplasticelastomer” in this embodiment may be the same as described in the secondaspect of the invention.

—Polystyrene-Based Thermoplastic Elastomer—

Examples of the polystyrene-based thermoplastic elastomer includematerials in which at least polystyrene constitutes a hard segment andanother polymer (such as polybutadiene, polyisoprene, polyethylene,hydrogenated polybutadiene, and hydrogenated polyisoprene) constitutes anon-crystalline soft segment with a low glass transition temperature.The “polystyrene-based thermoplastic elastomer” in this embodiment maybe the same as described in the second aspect of the invention.

—Polyurethane-Based Thermoplastic Elastomer—

Examples of the polyurethane-based thermoplastic elastomer includematerials in which at least polyurethane constitutes a hard segmentforming a pseudo-crosslink through physical agglomeration, and anotherpolymer constitutes a non-crystalline soft segment with a low glasstransition temperature. The “polyurethane-based thermoplastic elastomer”in this embodiment may be the same as described in the second aspect ofthe invention.

—Polyolefin-Based Thermoplastic Elastomer—

Examples of the polyolefin-based thermoplastic elastomer includematerials in which at least polyolefin constitutes a crystalline hardsegment with a high melting point, and another polymer (such as thepolyolefin, different polyolefin, and a polyvinyl compound) constitutesa non-crystalline soft segment with a low glass transition temperature.The “polyolefin-based thermoplastic elastomer” in this embodiment may bethe same as described in the second aspect of the invention.

An acid-denatured elastomer formed by acid denaturation of athermoplastic elastomer may be used as the thermoplastic elastomer.

An example of the “acid-denatured elastomer formed by acid denaturationof a thermoplastic elastomer” is an acid-denatured elastomer in which anacid group is introduced into the thermoplastic elastomer using acompound having an acid group. Examples of the compound having an acidgroup used to acid-modify the thermoplastic elastomer includeunsaturated compounds having an acid group such as a carboxylic group, asulfric acid group, and a phosphoric acid group. As the unsaturatedcompound having an acid group, an unsaturated compound having acarboxylic group which is a weak acid group is preferably used from theviewpoint of suppressing the degradation of the thermoplastic elastomer,and examples thereof include an acrylic acid, a methacrylic acid, anitaconic acid, a crotonic acid, an isocrotonic acid, and a maleic acid.

An example of the method of acid denaturation of the thermoplasticelastomer is a method of bonding the unsaturated bonding site of theunsaturated carboxylic acid to the olefin-based thermoplastic elastomeror the styrene-based thermoplastic elastomer through graftpolymerization or the like.

The thermoplastic resin material may include two or more kinds ofthermoplastic elastomers, but preferably includes one kind ofthermoplastic elastomer from the viewpoint of controlling the tireperformance of the tire formed using the thermoplastic resin material.

Among the above-mentioned thermoplastic elastomers, the polyamide-basedthermoplastic elastomer is preferably used from the viewpoint ofexcellent tensile modulus of elasticity, tensile strength, and fracturestrain and feasibility of fusing at a low temperature. From theviewpoint of excellent tensile modulus of elasticity, tensile strength,and fracture strain, as well as having high heat resistance, and a widetemperature setting range, the polyester-based thermoplastic elastomeris also preferably used. Among these, the polyamide-based thermoplasticelastomer is particularly preferably used as the thermoplastic elastomerin the fourth aspect of the invention.

—Physical Properties of Thermoplastic Elastomer—

The tensile modulus of elasticity, which is defined in JIS K7113:1995,of the thermoplastic resin material in the fourth aspect of theinvention is preferably from 100 MPa to 1000 MPa, more preferably from100 MPa to 800 MPa, and still more preferably from 100 MPa to 700 MPa.When the tensile modulus of elasticity of the thermoplastic resinmaterial is from 100 MPa to 1000 MPa, it is possible to efficientlyperforming fitting onto a rim while maintaining the shape of a tireframe. The elastic modulus is a value obtained by measuring adumbbell-shaped sample piece (sample piece No. 5) defined in JISK6251:1993 at a tensile rate of 200 mm/min by the use of ShimadzuAutograph AGS-J (5 kN) manufactured by Shimadzu Corporation.

The tensile yield strength, which is defined in JIS K7113:1995, of thethermoplastic resin material in the fourth aspect of the invention, ispreferably equal to or more than 5 MPa, more preferably from 5 to 20MPa, and still more preferably from 5 to 17 MPa. When the tensile yieldstrength of the thermoplastic resin material is equal to or more than 5MPa, it is possible to resist deformation due to a load applied to atire during traveling or the like.

The tensile yield elongation, which is defined in JIS K7113:1995, of thethermoplastic resin material in the fourth aspect of the invention ispreferably equal to or more than 10%, more preferably from 10% to 70%,and still more preferably from 15% to 60%. When the tensile yieldelongation of the thermoplastic resin material is equal to or more than10%, it is possible to increase an elastic region and to improvefittability onto a rim.

The tensile fracture elongation, which is defined in JIS K7113:1995, ofthe thermoplastic resin material in the fourth aspect of the inventionis preferably equal to or more than 50%, more preferably equal to ormore than 100%, still more preferably equal to or more than 150%, andstill more preferably equal to or more than 200%. When the tensilefracture elongation of the thermoplastic resin material is equal to ormore than 50%, it is possible to improve fittability onto a rim and tosuppress fracture due to collision.

The deflection temperature under load (under a load of 0.45 MPa), whichis defined in ISO 75-2 or ASTM D648, of the thermoplastic resin materialin the fourth aspect of the invention is preferably equal to or higherthan 50° C., more preferably from 50° C. to 150° C., and still morepreferably from 50° C. to 130° C. When the deflection temperature underload of the thermoplastic resin material is equal to or higher than 50°C., it is possible to suppress deformation of a tire frame in avulcanization step of a tread or the like.

The content of the thermoplastic elastomer in the thermoplastic resinmaterial in the fourth aspect of the invention is preferably from 40mass % to 95 mass % and more preferable from 50 mass % to 90 mass %,with respect to the total mass of the thermoplastic resin material, fromthe viewpoint of sufficient exhibition of performance of thethermoplastic elastomer.

The thermoplastic resin material may optionally contain variousadditives other than the specific needle-shaped crystal grains as longas they do not impair the effect of the fourth aspect of the invention.Examples of the additives include a filler, an anti-aging agent, oil, aplasticizer, a colorant, a weather resistant agent, and a reinforcingagent.

The thermoplastic resin material can be prepared as a mixture, forexample, by mixing the thermoplastic elastomer, the specificneedle-shaped crystal grains, and various additives which are optionallyused, and melting and kneading the resultant. The thermoplastic resinmaterial can be used optionally in a pellet shaped.

The tire of the fourth aspect of the invention includes a circular tireframe (hereinafter, appropriately also referred to as a “tire case”)formed of the above-mentioned thermoplastic resin material. The tireframe may be formed of the thermoplastic resin material into a unifiedbody using various forming methods or may be formed by forming a pair oftire case half parts (tire frame pieces) using various forming methodsand then bonding the tire case half parts. From the viewpoint ofproductivity, it is preferable that the tire frame is formed by bondinga pair of half case cases.

[Reinforcing Cord Layer]

The tire of the fourth aspect of the invention may have a reinforcingcord member which is wound on the outer circumferential portion of thetire frame in the circumferential direction to form a reinforcing cordlayer. The [Resin Material of Reinforcing Cord Layer] in the fourthaspect of the invention may be the same as the [Resin Material ofReinforcing Cord Layer] in the invention according to the first aspect.

Specific examples of the tire of the fourth aspect of the invention willbe described in more detail below with reference to Embodiments 4-1 and4-2.

Embodiment 4-1

A tire according to Embodiment 4-1 of the tire of the fourth aspect ofthe invention will be described below with reference to the accompanyingdrawings. Here, the tire according to Embodiment 4-1 is the same asdescribed in Embodiment 1-1, except for the following points.Accordingly, the same drawings and members will be described using thesame reference numerals and the same drawings.

The tire case 17 according to this embodiment is formed of athermoplastic resin material which is a mixture of a polyamide-basedthermoplastic elastomer (“UBESTA XPA9048” manufactured by UbeIndustries, Ltd.) and specific needle-shaped crystal grains (“MOS-HIGE”manufactured by Ube Material Industries Ltd.).

The content of the specific needle-shaped crystal grains in thethermoplastic resin material is 1 mass %.

The tire case 17 according to this embodiment is formed of athermoplastic resin material including a single thermoplastic elastomerand specific needle-shaped crystal grains, but the invention accordingto the fourth aspect is not limited to this configuration and theportions (such as the side portion 14, the crown portion 16, and thebead portion 12) of the tire case 17 may be formed of thermoplasticresin materials having different characteristics, similarly to typicalconventional rubber pneumatic tires. A reinforcing material (such asfiber, cord, unwoven fabric, and woven fabric which are formed of apolymer material or metal) may be embedded in the tire case 17 (such asthe bead portion 12, the side portion 14, and the crown portion 16) toreinforce the tire case 17 with the reinforcing material.

The tire case 17 according to this embodiment is formed by bonding apair of tire case half parts (tire frame pieces) 17A formed of thethermoplastic resin material including a thermoplastic elastomer andspecific needle-shaped crystal grains to each other. The tire case halfparts 17A are formed by opposing circular tire case half parts 17A, ineach of which one bead portion 12, one side portion 14, and a half-widthcrown portion 16 are formed as a unified body by injection molding orthe like, having the same shape to each other and bonding both tire casehalf parts to each other at the tire equatorial plane portion. The tirecase 17 is not limited to bonding two members, but may be formed bybonding three or more members. The others are the same as the tireaccording to Embodiment 1-1 and the production method thereof is alsothe same.

(Effects)

In the tire 10 according to this embodiment, since the tire case 17 isformed of the thermoplastic resin material including a thermoplasticelastomer and specific needle-shaped crystal grains, the loss factor(tan δ) of the tire frame is kept low and the elastic modulus isimproved, compared with a case where a thermoplastic resin materialincluding only the thermoplastic elastomer is used. Accordingly, thetire 10 has a high elastic modulus and has reduced rolling resistance.The tire 10 also has excellent heat resistance. Since the tire 10 has asimpler structure than a conventional rubber tire, the weight issmaller. Accordingly, the tire 10 according to this embodiment hasexcellent abrasion resistance and durability.

In the tire 10 according to this embodiment, since the reinforcing cord26 having rigidity higher than the resin material is wound on the outercircumferential surface of the crown portion 16 of the tire case 17formed of a thermoplastic resin material helically in thecircumferential direction, puncture resistance, cutting resistance, andrigidity in the circumferential direction of the tire 10 are improved.Since the rigidity in the circumferential direction of the tire 10 isimproved, it is possible to prevent creeping of the tire case 17 formedof a thermoplastic resin material.

Since at least a part of the reinforcing cord 26 is embedded in theouter circumferential surface of the crown portion 16 of the tire case17 formed of the thermoplastic resin material and comes in close contactwith the resin material in a cross-sectional view (the cross-sectionshown in FIG. 1) taken along the axial direction of the tire case 17,the air inclusion at the time of production is suppressed and themovement of the reinforcing cord 26 due to a force applied thereto atthe time of traveling is suppressed. Accordingly, it is possible tosuppress abrasion of the reinforcing cord 26, the tire case 17, and thetread 30 and thus to improve durability of the tire 10.

In this way, when the reinforcing cord layer 28 is formed to include theresin material, it is possible to reduce the difference in hardnessbetween the tire case 17 and the reinforcing cord layer 28 and thus tofurther closely contact and fix the reinforcing cord 26 with and to thetire case 17, compared with a case where the reinforcing cord 26 isfixed merely using the cushion rubber. Accordingly, it is possible toeffectively prevent the above-mentioned air inclusion and thus toeffectively suppress the movement of the reinforcing cord member at thetime of traveling.

When the reinforcing cord 26 is a steel cord, the reinforcing cord 26can be easily separated and recovered from the resin material by heatingat the time of disposal of the tire and thus it is advantageous in viewof recyclability of the tire 10. The resin material usually has a lowerloss factor (tan δ) compared with a vulcanized rubber. Accordingly, whenthe reinforcing cord layer 28 contains a large amount of resin material,it is possible to enhance the rolling properties of the tire. The resinmaterial is more advantageous in that the resin material has highin-plane shear stiffness and has excellent steering stability andabrasion resistance at the time of traveling with the tire, comparedwith a vulcanized rubber.

As shown in FIG. 2, since the depth L of embedding of the reinforcingcord 26 is set to be equal to or more than ⅕ of the diameter D thereof,it is possible to effectively suppress the air inclusion at the time ofproduction and to further suppress the movement of the reinforcing cord26 due to a force applied thereto at the time of traveling.

Since the tread 30 coming in contact with a road surface is formed of arubber material having abrasion resistance higher than the resinmaterial including first and second thermoplastic elastomers, theabrasion resistance of the tire 10 is enhanced.

Since the anuular bead core 18 formed of a metal material is embedded inthe bead portion 12, the tire case 17, that is, the tire 10, is stronglyretained in the rim 20, similarly to a conventional rubber pneumatictire.

Since the sealing layer 24 formed of a rubber material having highersealability than the resin material forming the tire case 17 is disposedin the part of the bead portion 12 coming in contact with the rim 20,the sealability between the tire 10 and the rim 20 is improved.Accordingly, compared with a case where the sealing is performed withthe rim 20 and the resin material forming the tire case 17, air leakagefrom the tire is further suppressed. By disposing the sealing layer 24,fittability onto a rim are also improved.

Although it is stated in Embodiment 4-1 that the reinforcing cord 26 isheated to melt or soften the thermoplastic resin material in the partcoming in contact with the heated reinforcing cord 26, the inventionaccording to the fourth aspect is not limited to this configuration, butthe outer circumferential surface of the crown portion 16 where thereinforcing cord 26 is to be embedded therein may be heated using a hotair generating device, and then the reinforcing cord 26 may be embeddedin the crown portion 16, instead of heating the reinforcing cord 26.

Although the heater and the fan are adopted as the heat source of thecord heating device 59 in Embodiment 4-1, the invention according to thefourth aspect is not limited to this configuration, but the reinforcingcord 26 may be directly heated with radiation heat (for example,infrared rays).

Although the melted or softened portion of the thermoplastic resinmaterial having the reinforcing cord 26 embedded therein is forciblycooled with the second roller 64 formed of metal in Embodiment 4-1, theinvention according to the fourth aspect is not limited to thisconfiguration, but cold air may be directly applied to the melted orsoftened portion of the thermoplastic resin material to forcibly cooland solidify the melted or softened portion of the thermoplastic resinmaterial.

Although the reinforcing cord 26 is heated in Embodiment 4-1, forexample, the outer circumference of the reinforcing cord 26 may becoated with the same thermoplastic resin material as the tire case 17.In this case, by heating the coated thermoplastic resin material alongwith the reinforcing cord 26 when the coated reinforcing cord is woundon the crown portion 16 of the tire case 17, it is possible toeffectively suppress the incorporation of air at the time of embeddingthe reinforcing cord in the crown portion 16.

The helical winding of the reinforcing cord 26 is easy in production,but it can also be considered that the reinforcing cord 26 is wounddiscontinuously in the width direction.

The tire 10 according to Embodiment 4-1 is a so-called tubeless tire inwhich an air chamber is formed between the tire 10 and the rim 20 byfitting the bead portion 12 to the rim 20. However, the inventionaccording to the fourth aspect is not limited to this configuration, butthe tire may have a complete tube shape.

In the complete tube-like tire, for example, as shown in FIG. 4, threetire frames having a circular shape may be arranged in the tire widthdirection. FIG. 4 is a cross-sectional view of a tire according toanother embodiment. As shown in FIG. 4, a tire 86 includes a treadrubber layer 87, circular hollow tubes (tire frames) 88 formed of thesame resin material as described in Embodiment 4-1, a belt (reinforcingcord) 89, and a rim 90. Three tubes 88 are arranged side by side in thetire width direction of the tire 86. The tread rubber layer 87 in whichthe belt 89 is embedded is bonded to the outer circumference of thetubes 88. The tubes 88 are fitted to the rim 90 having concave portionsengaging with the tubes 88. The tire 86 is not provided with a beadcore.

While the invention according to the fourth aspect has been describedwith reference to the embodiments, the embodiments are only an exampleand can be modified in various forms without departing from the conceptthereof. The scope of the fourth aspect of the invention is not limitedto the embodiments.

Embodiment 4-2

An Embodiment 4-2 of the tire of the fourth aspect of the invention willbe described below with reference to the accompanying drawings.

Here, the tire according to Embodiment 4-2 is the same as described inEmbodiment 1-2, except for the following points. Accordingly, the samedrawings and members will be described using the same reference numeralsand the same drawings.

Similarly to Embodiment 4-1, the tire case 17 of the tire according toEmbodiment 4-2 is formed of a thermoplastic resin material which is amixture of a polyamide-based thermoplastic elastomer (“UBESTA XPA9048”made by Ube Industries, Ltd.) and specific needle-shaped crystal grains(“MOS-HIGE” made by Ube Material Industries Ltd.).

The content of the specific needle-shaped crystal grains in thethermoplastic resin material is 1 mass %. The other is the same as thetire according to Embodiment 1-2 and the production method thereof isalso the same.

(Effects)

In the tire 200 according to this embodiment, since the tire case 17 isformed of the thermoplastic resin material which is a mixture of apolyamide-based thermoplastic elastomer and specific needle-shapedcrystal grains, the loss factor (tan δ) of the tire frame is kept lowand the elastic modulus is improved, compared with a case where only thepolyamide-based thermoplastic elastomer is used. Accordingly, the tire200 has a high elastic modulus and has reduced rolling resistance. Thetire 200 also has excellent heat resistance. Since the tire 200 has asimpler structure than a conventional rubber tire, the weight issmaller. Accordingly, the tire 200 according to this embodiment hasexcellent abrasion resistance and durability.

In the method for producing a tire according to this embodiment, inunifying the tire case 17, the cushion rubber 29, and the tread rubber30A, the outer circumferential surface 17S of the tire case 17 has beensubjected to a roughening treatment and thus the adhesiveness (bondingproperties) is improved by the anchor effect. Since the resin materialforming the tire case 17 is indented due to the collision of theblasting abrasive, the wettability of the adhesive is improved.Accordingly, the adhesive is uniformly applied to the outercircumferential surface 17S of the tire case 17 and this state isretained, whereby it is possible to secure the bonding strength betweenthe tire case 17 and the cushion rubber 29.

Particularly, even when unevenness is formed on the outercircumferential surface 17S of the tire case 17, the blasting abrasiveis made to collide with the concave portions (the gaps 28A) to performthe roughening treatment on the peripheries (concave walls, concavebottoms) of the concave portions, whereby it is possible to secure thebonding strength between the tire case 17 and the cushion rubber 29.

On the other hand, since the cushion rubber 29 is stacked in theroughened region of the outer circumferential surface 17S of the tirecase 17, it is possible to effectively secure the bonding strengthbetween the tire case 17 and the cushion rubber.

When the cushion rubber 29 is vulcanized in the vulcanization step, thecushion rubber 29 flows in the roughened unevenness formed on the outercircumferential surface 17S of the tire case 17 through the rougheningtreatment. When the vulcanization is completed, an anchor effect isexhibited by the cushion rubber 29 flowing in the roughened unevenness,and the bonding strength between the tire case 17 and the cushion rubber29 is enhanced.

In the tire 200 produced by this method for producing a tire, thebonding strength between the tire case 17 and the cushion rubber 29 issecured. That is, the bonding strength between the tire case 17 and thetread 30 is secured through the cushion rubber 29. Accordingly, theabrasion of the outer circumferential surface 17S of the tire case 17 ofthe tire 200 from the cushion rubber 29 is suppressed.

Since the outer circumferential portion of the tire case 17 is formed ofthe reinforcing cord layer 28, puncture resistance and cuttingresistance are improved, compared with a case where the outercircumferential portion is formed of a member other than the reinforcingcord layer 28.

Since the coated cord member 26B is wound to form the reinforcing cordlayer 28, the rigidity in the circumferential direction of the tire 200is improved. Since the rigidity in the circumferential direction isimproved, creeping of the tire case 17 (a phenomenon in which theplastic deformation of the tire case 17 increases with the lapse of timeunder a constant stress) is suppressed and pressure resistance to airpressure from the inside in the tire diameter direction is improved.

When the reinforcing cord layer 28 is formed to include the coated cordmember 26B, it is possible to reduce the difference in hardness betweenthe tire case 17 and the reinforcing cord layer 28 and thus to furtherclosely bring and fix the coated cord member 26B in contact with and tothe tire case 17, compared with a case where the reinforcing cord 26A isfixed merely using the cushion rubber 29. Accordingly, it is possible toeffectively prevent the above-mentioned incorporation of air and thus toeffectively suppress the movement of the reinforcing cord member at thetime of traveling.

When the reinforcing cord 26A is a steel cord, the cord member 26A canbe easily separated and recovered from the coated cord member 26B byheating at the time of disposal of the tire and thus it is advantageousin view of recyclability of the tire 200. The resin material has a lowerloss factor (tan δ) compared with a vulcanized rubber. Accordingly, whenthe reinforcing cord layer 28 contains a large amount of resin material,it is possible to enhance the rolling properties of the tire. The resinmaterial is more advantageous in that the resin material has highin-plane shear stiffness and has excellent steering stability andabrasion resistance at the time of traveling with the tire, comparedwith a vulcanized rubber.

Although unevenness is formed on the outer circumferential surface 17Sof the tire case 17 in this embodiment, the invention according to thefourth aspect is not limited to this configuration, but the outercircumferential surface 17S may be formed to be flat.

In the tire case 17, the coated cord member wound on and bonded to thecrown portion of the tire case may be covered with a coatingthermoplastic material to form a reinforcing cord layer. In this case,the melted or softened coating thermoplastic material may be ejectedonto the reinforcing cord layer 28 to form a coating layer. A weldingsheet may be heated into a melted or softened state without using anextruder and may be attached to the surface (the outer circumferentialsurface) of the reinforcing cord layer 28 to form a coating layer.

Although the tire case half parts 17A are bonded to form the tire case17 in Embodiment 4-2, the invention according to the fourth aspect isnot limited to this configuration, but the tire case 17 may be formed asa unified body using a mold or the like.

The tire 200 according to Embodiment 4-2 is a so-called tubeless tire inwhich an air chamber is formed between the tire 200 and the rim 20 byfitting the bead portion 12 to the rim 20. However, the inventionaccording to the fourth aspect is not limited to this configuration, butthe tire 200 may have, for example, a complete tube shape (for example,the shape shown in FIG. 4).

Although the cushion rubber 29 is interposed between the tire case 17and the tread 30 in Embodiment 4-2, the invention according to thefourth aspect is not limited to this configuration, but the cushionrubber 29 may not be interposed therebetween.

Although the coated cord member 26B is helically wound on the crownportion 16 in Embodiment 4-2, the invention according to the fourthaspect is not limited to this configuration, but the coated cord member26B may be wound thereon to be discontinuous in the width direction.

In Embodiment 4-2, a thermoplastic material is used as the coating resinmaterial 27 forming the coated cord member 26B, the coating resinmaterial 27 is melted or softened by heating, and the coated cord member26B is welded to the outer circumferential surface of the crown portion16. However, the invention according to the fourth aspect is not limitedto this configuration, but the coated cord member 26B may be bonded tothe outer circumferential surface of the crown portion 16 using anadhesive or the like without heating the coating resin material 27.

A thermosetting resin may be used as the coating resin material 27forming the coated cord member 26B, and the coated cord member 26B maybe bonded to the outer circumferential surface of the crown portion 16using an adhesive or the like without heating the coated cord member26B.

A thermosetting resin may be used as the as the coating resin material27 forming the coated cord member 26B and the tire case 17 may be formedof a thermoplastic resin material. In this case, the coated cord member26B may be bonded to the outer circumferential surface of the crownportion 16 using an adhesive or the like, or a part of the tire case 17in which the coated cord member 26B is embedded may be heated to be in amelted or softened state and the coated cord member 26B may be welded tothe outer circumferential surface of the crown portion 16.

A thermoplastic resin may be used as the as the coating resin material27 forming the coated cord member 26B and the tire case 17 may be formedof a thermoplastic resin material. In this case, the coated cord member26B may be bonded to the outer circumferential surface of the crownportion 16 using an adhesive or the like, or a part of the tire case 17in which the coated cord member 26B is embedded may be heated into amelted or softened state, the coating resin material 27 is heated to bein a melted or softened state, and the coated cord member 26B may bewelded to the outer circumferential surface of the crown portion 16.When both the tire case 17 and the coated cord member 26B may be heatedto be in a melted or softened state, both are mixed with each other welland thus the bonding strength therebetween is improved. When athermoplastic resin material is used as the resin material forming thetire case 17 and a thermoplastic resin material is used as the coatingresin material 27 forming the coated cord member 26B, the same kind ofthermoplastic material, particularly, the same thermoplastic material,is preferably used.

The outer circumferential surface 17S of the tire case 17 may beactivated to enhance the hydrophilic property by performing a coronatreatment or a plasma treatment on the outer circumferential surfacehaving been subjected to the roughening treatment, and then an adhesivemay be applied thereto.

The sequence for producing the tire 200 is not limited to the sequencedescribed in Embodiment 4-2, but may be appropriately changed.

While the invention according to the fourth aspect has been describedwith reference to the embodiments, the embodiments are only an exampleand can be modified in various forms without departing from the conceptthereof. The scope of the fourth aspect of the invention is not limitedto the embodiments.

<<Fifth Aspect of the Invention>>

A resin material forming a tire frame in the invention according to afifth aspect will be described, and specific embodiments of a tire ofthe fifth aspect of the invention will be then described with referenceto the accompanying drawings.

[Resin Material]

A tire of the fifth aspect of the invention includes a circular tireframe formed of at least a resin material, and the resin materialincludes a thermoplastic elastomer including a hard segment and a softsegment in a molecule thereof and a resin of which the glass transitiontemperature (Tg) is higher than the glass transition temperature of thehard segment.

Here, the “resin material” in this description is a concept whichencompasses a thermoplastic resin (including a thermoplastic elastomer)and a thermosetting resin as described above, but does not encompass avulcanized rubber.

As described above, examples of the thermosetting resin which can beused in the reinforcing cord layer include a phenol resin, a urea resin,a melamine resin, an epoxy resin, a polyamide resin, and a polyesterresin.

As described above, examples of the thermoplastic resin include aurethane resin, an olefin resin, a vinylchloride resin, a polyamideresin, and a polyester resin.

As described above, the “thermoplastic elastomer” means a thermoplasticresin material including a copolymer having a polymer constituting acrystalline hard segment with a high melting point or a hard segmentwith a high cohesive force and a polymer constituting a non-crystallinesoft segment with a low glass transition temperature, in a moleculethereof.

Since the tire of the fifth aspect of the invention employs a resinmaterial including a thermoplastic elastomer including a hard segmentand a soft segment in a molecule thereof and a resin having a higherglass transition temperature (Tg) than the hard segment, it is possibleto keep the loss factor (tan δ) of the tire frame low and to improve theheat resistance thereof.

A case where PAE (polyamide-based thermoplastic elastomer) is used asthe thermoplastic elastomer and polyphenylene ether (PPE) is used as aspecific resin in the fifth aspect of the invention will be describedwith reference to FIG. 10. FIG. 10 is a diagram illustrating arelationship between the glass transition temperature and the lossfactor (tan δ) in each material. In FIG. 10, a solid line indicating theglass transition temperature (Tg_(PA/PPE)) of PAE/PPE which is anembodiment of the fifth aspect of the invention, a one-dotted lineindicating the glass transition temperature (Tg_(PAE)) of PAE, a smalldotted line indicating the glass transition temperature (Tg_(PA)) ofpolyamide, and a large dotted line indicating the glass transitiontemperature (Tg_(PPE)) of PPE are illustrated, and the glass transitiontemperatures of the materials are shown as peaks of the lines.

In the fifth aspect of the invention, the resin material in which thethermoplastic elastomer (PAE) and the specific resin (PPE) of the fifthaspect of the invention, that is, PAE/PPE which is an embodiment of thefifth aspect of the invention has a higher glass transition temperaturethan polyamide constituting the hard segment of the thermoplasticelastomer and it is thus possible to enhance the heat resistance, whichcan be seen from the comparison of the peak of Tg_(PA) and the peak ofTg_(PAE/PPE) in FIG. 10. In general, when the heat resistance of thethermoplastic elastomer is enhanced, the loss factor (tan δ) alsoincreases therewith. However, the PAE/PPE which is an embodiment of thefifth aspect of the invention can keep the loss factor lower than thethermoplastic elastomer (PAE) and polyamide constituting the hardsegment thereof, as indicated by an arrow at the center of FIG. 10. Thatis, like the resin material in the fifth aspect of the invention, byusing the thermoplastic elastomer and the specific resin in the fifthaspect of the invention of which the glass transition temperature ishigher than that of the hard segment thereof, it is possible to keep theloss factor (tan δ) low and to enhance the heat resistance of the tireframe.

(Thermoplastic Elastomer)

Examples of the thermoplastic elastomer include a polyamide-basedthermoplastic elastomer (TPA), a polyester-based thermoplastic elastomer(TPC), a polyolefin-based thermoplastic elastomer (TPO), apolystyrene-based thermoplastic elastomer (TPS), a polyurethane-basedthermoplastic elastomer (TPU), a thermoplastic cross-linked rubber(TPV), and other thermoplastic elastomers (TPZ), which are defined inJIS K6418:2007.

The same kind of resin material in the below description means an aspectof between ester-based resin material and ester-based resin material, anaspect of between styrene-based resin material and styrene-based resinmaterial, and the like.

—Polyamide-Based Thermoplastic Elastomer—

The “polyamide-based thermoplastic elastomer” in this embodiment may bethe same polyamide-based thermoplastic elastomer as described in thefirst aspect of the invention.

—Polystyrene-Based Thermoplastic Elastomer—

Examples of the polystyrene-based thermoplastic elastomer includematerials in which at least polystyrene constitutes a hard segment andanother polymer (such as polybutadiene, polyisoprene, polyethylene,hydrogenated polybutadiene, and hydrogenated polyisoprene) constitutes anon-crystalline soft segment with a low glass transition temperature.The “polystyrene-based thermoplastic elastomer” in this embodiment maybe the same as described in the second aspect of the invention.

—Polyurethane-Based Thermoplastic Elastomer—

Examples of the polyurethane-based thermoplastic elastomer includematerials in which at least polyurethane constitutes a hard segmentforming a pseudo-crosslink through physical agglomeration and anotherpolymer constitutes a non-crystalline soft segment with a low glasstransition temperature. The “polyurethane-based thermoplastic elastomer”in this embodiment may be the same as described in the second aspect ofthe invention.

—Polyolefin-Based Thermoplastic Elastomer—

Examples of the polyolefin-based thermoplastic elastomer includematerials in which at least polyolefin constitutes a crystalline hardsegment with a high melting point and another polymer (such as thepolyolefin described above, another polyolefin, and a polyvinylcompound) constitutes a non-crystalline soft segment with a low glasstransition temperature. The “polyolefin-based thermoplastic elastomer”in this embodiment may be the same as described in the second aspect ofthe invention.

—Polyester-Based Thermoplastic Elastomer—

Examples of the polyester-based thermoplastic elastomer includematerials in which at least polyester constitutes a crystalline hardsegment with a high melting point and another polymer (such as polyesterand polyether) constitutes a non-crystalline soft segment with a lowglass transition temperature. The “polyester-based thermoplasticelastomer” in this embodiment may be the same as described in the secondaspect of the invention.

—Physical Properties of Thermoplastic Elastomer—

The thermoplastic elastomer included in the resin material forming thetire frame of the fifth aspect of the invention can be appropriatelyselected so as to exhibit desired tire performance. Here, the elasticmodulus (the tensile modulus of elasticity defined in JIS K7113:1995) ofthe thermoplastic elastomer included in the resin material is preferablyfrom 1 MPa to 150 Mpa and more preferably from 1 MPa to 60 MPa, inconsideration of the viewpoint of tire performance and the viewpoint ofthe loss factor (tan δ) required for the tire.

Similarly, tan δ of the thermoplastic elastomer in the fifth aspect ofthe invention is preferably from 0.01 to 0.1 and more preferably from0.01 to 0.08. Here, the “loss factor (tan δ)” is a value calculated by aratio (G″/G′) between the storage shear elastic modulus (G′) and theloss shear elastic modulus (G″) at 30° C., 20 Hz, and 1% of shearingstrain and is a value representing a degree to which a material absorbsenergy (converts into heat) when the material is deformed. Since thelarger tan δ causes absorption of more energy, the rolling resistance ofthe tire increases and consequently serves as a reason of degradation infuel efficiency of the tire. The value of tan δ of the thermoplasticelastomer can be measured by the use of a dynamic viscoelasticitymeasuring apparatus (Dynamic-Mechanical Analysis: DMA).

The glass transition temperature (Tg) of the hard segment of thethermoplastic elastomer in the fifth aspect of the invention ispreferably from 0° C. to 150° C. and more preferably from 30° C. to 120°C., from the viewpoint of treatment in injection molding andproductivity and the value of tan δ.

The glass transition temperature of the hard segment can be measuredthrough differential scanning calorimetry (DSC). In the fifth aspect ofthe invention, the glass transition temperature of the “hard segment”means the glass transition temperature of a polymer alone that forms thehard segment.

At least one kind selected from a polyamide-based thermoplasticelastomer or a polyester-based thermoplastic elastomer may be preferablyused as the thermoplastic elastomer, from the viewpoint of the elasticmodulus, tan δ and a combination with a resin to be described later.

More specifically, a thermoplastic elastomer having polyethylene (Tg:−125° C.), polyacetal (Tg: −60° C.), an ethylene vinyl acetate copolymer(Tg: −42° C.), polyurethane (Tg: −20° C.), polypropylene (Tg: 0° C.),polyvinylidene fluoride (Tg: 35° C.), polyamide 6 (so-called nylon 6,Tg: 48° C.), polyamide 12 (so-called nylon 12, Tg: 51° C.), polyamide 46(so-called nylon 46, Tg: 78° C.), polyamide 66 (so-called nylon 66, Tg:50° C.), polybutylene terephthalate (Tg: 50° C.), polylactic acid (Tg:57° C.), polyethylene terephthalate (Tg: 59° C.), a polyacrylonitrilebutadiene styrene copolymer (Tg: 80 to 125° C.), polyvinyl chloride (Tg:87° C.), methyl polymethacrylate (Tg: 90° C.), polystyrene (Tg: 100°C.), polyacrylonitrile (Tg: 104° C.), polyphenylene oxide (PPO, Tg: 104°C. to 120° C.), polyphenylene sulfide (Tg: 92° C.),polytetrafluoroethylene (Tg: 126° C.), polycarbonate (Tg: 150° C.),polyethersulfone (Tg: 230° C.), polyamideimide (Tg: 275° C.), orpolyarylate (Tg: 176° C.) as a hard segment may be preferably used, anda thermoplastic elastomer having polyphenylene oxide, polyphenylenesulfide, polybutylene terephthalate, polyethylene terephthalate,polycarbonate, or polyarylate may be more preferably used.

(Specific Resin According to Fifth Aspect of the Invention)

The “specific resin of the fifth aspect of the invention” is a resin ofwhich the glass transition temperature (Tg) is higher than that of thehard segment.

Accordingly, in the tire of which the tire frame is formed of the resinmaterial including the thermoplastic elastomer and the specific resin ofthe fifth aspect of the invention, it is possible to keep tan δ of thetire frame low and to enhance the elastic modulus. Accordingly, forexample, it is possible to enhance the elastic modulus (heat resistance)while reducing the rolling resistance of the tire. When the glasstransition temperature of the specific resin of the fifth aspect of theinvention is lower than the glass transition temperature of the hardsegment, the elastic modulus or the heat resistance of the tire framecannot be enhanced.

The specific resin of the fifth aspect of the invention is notparticularly limited as long as the glass transition temperature thereofis higher than that of the hard segment, and can appropriately employknown resins as long as they do not impair the effect of the fifthaspect of the invention. However, for example, it is preferable tosatisfy the following physical properties.

The glass transition temperature (Tg) of the specific resin of the fifthaspect of the invention differs depending on the combination of athermoplastic elastomer to be used and the specific resin of the fifthaspect of the invention, but is preferably from 0° C. to 300° C. andmore preferably from 30° C. to 200° C., from the viewpoint ofproductivity (treatment) in molding the tire frame.

The glass transition temperature of the specific resin of the fifthaspect of the invention has only to be higher than that of the hardsegment of the thermoplastic elastomer. The glass transition temperature(Tg₁) of the specific resin of the fifth aspect of the invention ispreferably higher, by 20° C. or more, than the glass transitiontemperature (Tg₂) of the hard segment. More specifically, the difference(Tg₁−Tg₂) between the glass transition temperature (Tg₁) of the specificresin of the fifth aspect of the invention and the glass transitiontemperature (Tg₂) of the hard segment differs depending on thecombination of the thermoplastic elastomer to be used and the specificresin of the fifth aspect of the invention, but is preferably 20° C. to200° C. and more preferably 30° C. to 80° C., from the viewpoint ofproductivity (treatment) in molding the tire frame.

The elastic modulus (the tensile modulus of elasticity defined in JISK7113:1995) of the specific elastomer of the fifth aspect of theinvention is preferably from 100 MPa to 2000 Mpa and more preferablyfrom 400 MPa to 1200 MPa, in consideration of the viewpoint of tireperformance and the viewpoint of the loss factor (tan δ) required forthe tire.

Similarly, tan δ of the specific resin of the fifth aspect of theinvention is preferably from 0.01 to 0.1 and more preferably from 0.01to 0.06. The value of tan δ of the specific resin of the fifth aspect ofthe invention can be measured by the use of a dynamic viscoelasticitymeasuring apparatus (Dynamic-Mechanical Analysis: DMA).

As the specific resin according to the fifth aspect of the presentinvention, for example, polyphenylene ether (PPE, Tg: 210° C.),polyethylene (Tg: −125° C.), polyacetal (Tg: −60° C.), ethylene vinylacetate copolymer (Tg: −42° C.), polyurethane (Tg: −20° C.),polypropylene (Tg: 0° C.), polyvinylidene fluoride (Tg: 35° C.),polyamide 6 (so-called nylon 6, Tg: 48° C.), polyamide 12 (so-callednylon 12, Tg: 51° C.), polyamide 46 (so-called nylon 46, Tg: 78° C.),polyamide 66 (so-called nylon 66, Tg: 50° C.), polybutyleneterephthalate (Tg: 50° C.), polylactic acid (Tg: 57° C.), polyethyleneterephthalate (Tg: 59° C.), a polyacrylonitrile butadiene styrenecopolymer (Tg: 80 to 125° C.), polyvinyl chloride (Tg: 87° C.), methylpolymethacrylate (Tg: 90° C.), polystyrene (Tg: 100° C.),polyacrylonitrile (Tg: 104° C.), polyphenylene oxide (PPO, Tg: 104 to120° C.), polyphenylene sulfide (Tg: 92° C.), polytetrafluoroethylene(Tg: 126° C.), polycarbonate (Tg: 050° C.), polyethersulfone (Tg: 230°C.), and polyamideimide (Tg: 275° C.) are preferred, and polyphenyleneether, polyphenylene sulfide, polyethylene terephthalate, polybutyleneterephthalate, polyethylene naphthalate, polybutylene naphthalate,polytrimethylene terephthalate, polycarbonate and polyarylate are morepreferred.

Furthermore, as a combination of the thermoplastic elastomer with thespecific resin according to the fifth aspect of the present invention,from the viewpoint of increasing the elastic modulus while maintaining alow loss coefficient (Tan δ), in addition to a combination of apolyamide-based thermoplastic elastomer with polyphenylene ether, acombination of a polyamide-based thermoplastic elastomer with any one ofpolyphenylene sulfide, polyethylene terephthalate, polybutyleneterephthalate, polyethylene naphthalate, polybutylene naphthalate,polytrimethylene terephthalate, polycarbonate, polyarylate, and apolystyrene-based resin; and a combination of a polyester-basedthermoplastic elastomer with any one of polyphenylene ether,polyphenylene sulfide, polyethylene terephthalate, polybutyleneterephthalate, polyethylene naphthalate, polybutylene naphthalate,polytrimethylene terephthalate, polycarbonate, and polyarylate; arepreferred.

(Resin Materials)

In the resin material including the thermoplastic elastomer and thespecific resin according to the fifth aspect of the present invention,the content ratio between the thermoplastic elastomer and the specificresin according to the fifth aspect of the present invention can bedetermined on the basis of the mass ratio (x+y:z) of the total (x+y) ofthe hard segment (x) of the thermoplastic elastomer and the resin (y)with respect to the soft segment of the thermoplastic elastomer (z). Themass ratio (x+y:z) is preferably from 10:90 to 90:10, and morepreferably from 40:60 to 80:20. If the mass ratio (x+y:z) is in therange of 10:90 to 90:10, the effect of improving the elastic moduluswhile maintaining a low Tan δ of the tire frame can be satisfactoryobtained.

Moreover, the mass ratio (x:y) between the hard segment (x) of thethermoplastic elastomer and the specific resin (y) according to thefifth aspect of the present invention is preferably from 90:10 to 30:70,and more preferably from 80:20 to 40:60, in view of a balance of thetensile modulus of elasticity and the tan δ, and the processingcharacteristics due to the difference in the respective melting points.

The melting point of the resin material including the thermoplasticelastomer and the specific resin of the fifth aspect of the invention isusually 100° C. to 350° C. and preferably 100° C. to 250° C. From theviewpoint of productivity of the tire, the melting point is preferably120° C. to 250° C. and more preferably 150° C. to 200° C. In this way,by using the thermoplastic resin material including a thermoplasticelastomer of which the melting point is 120° C. to 250° C., it ispossible to set the heating temperature of the junction thereof to equalto or higher than the melting point of the thermoplastic resin materialforming the tire frame, for example, when the tire frame is formed bywelding the divided bodies (frame) thereof. Since the tire of the fifthaspect of the invention employs the thermoplastic resin materialincluding the thermoplastic elastomer, the bonding strength between thetire frame pieces is sufficient even in the tire frame welded in thetemperature range of 120° C. to 250° C. Accordingly, the tire of thefifth aspect of the invention has superior durability in traveling, suchas puncture resistance or abrasion resistance. The heating temperatureis preferably a temperature higher, by 10° C. to 150° C., than themelting point of the thermoplastic resin material including thethermoplastic elastomer forming the tire frame pieces and morepreferably a temperature higher by 10° C. to 100° C.

The total content of the thermoplastic elastomer and the specific resinof the fifth aspect of the invention in the resin material in the fifthaspect of the invention is not particularly limited, but is preferablyequal to or more than 50 mass % and more preferably equal to or morethan 90 mass %, with respect to the total content of the resin material.When the total content of the thermoplastic elastomer and the specificresin of the fifth aspect of the invention is 50 mass % to 100 mass %with respect to the total content of the resin material, the effect ofuse of the thermoplastic elastomer and the specific resin of the fifthaspect of the invention can be satisfactorily exhibited. A rubber,another thermoplastic elastomer, a thermosetting resin, various fillers(such as silica, calcium carbonate, and clay) and various additives suchas an anti-aging agent, oil, a plasticizer, a colorant, a weatherresistant agent, and a reinforcing agent may be optionally added to theresin material.

The resin material can be obtained by mixing the thermoplastic elastomerand the specific resin of the fifth aspect of the invention, addingvarious additives thereto optionally, and appropriately mixing theresultant using a known method (such as a melting and mixing method).The thermoplastic resin material obtained by melting and mixing can beoptionally used as a pellet shape.

The tensile modulus of elasticity, which is defined in JIS K7113:1995,of the resin material including the thermoplastic elastomer and thespecific resin of the fifth aspect of the invention is preferably 100 to1000 MPa, more preferably 100 to 800 MPa, and still more preferably 100to 700 MPa. When the tensile modulus of elasticity of the resin materialis 100 to 1000 MPa, it is possible to efficiently fit onto a rim whilemaintaining the shape of a tire frame.

The tensile yield strength, which is defined in JIS K7113:1995, of theresin material including the thermoplastic elastomer and the specificresin of the fifth aspect of the invention is preferably equal to ormore than 5 MPa, more preferably 5 to 20 MPa, and still more preferably5 to 17 MPa. When the tensile yield strength of the resin material isequal to or more than 5 MPa, it is possible to resist deformation due toa load applied to a tire during traveling or the like.

The tensile yield elongation, which is defined in JIS K7113:1995, of theresin material including the thermoplastic elastomer and the specificresin of the fifth aspect of the invention is preferably equal to ormore than 10%, more preferably 10% to 70%, and still more preferably 15%to 60%. When the tensile yield elongation of the resin material is equalto or more than 10%, it is possible to increase an elastic region and toimprove fittability onto a rim.

The tensile fracture elongation, which is defined in JIS K7113:1995, ofthe resin material including the thermoplastic elastomer and thespecific resin of the fifth aspect of the invention is preferably equalto or more than 50%, more preferably equal to or more than 100%, stillmore preferably equal to or more than 150%, and still more preferablyequal to or more than 200%. When the tensile fracture elongation of theresin material is equal to or more than 50%, it is possible to improvefittability onto a rim and to suppress fracture due to collision.

The deflection temperature under load (under a load of 0.45 MPa), whichis defined in ISO 75-2 or ASTM D648, of the resin material including thethermoplastic elastomer and the specific resin of the fifth aspect ofthe invention is preferably equal to or higher than 50° C., morepreferably 50° C. to 150° C., and still more preferably 50° C. to 130°C. When the deflection temperature under load of the resin material isequal to or higher than 50° C., it is possible to suppress deformationof a tire frame even in the case in which a vulcanization step isincluded in the production of the tire.

Embodiment 5-1

A tire according to Embodiment 5-1 of the tire of the fifth aspect ofthe invention will be described below with reference to the accompanyingdrawings. Here, the tire according to Embodiment 5-1 is the same asdescribed in Embodiment 1-1, except for the following points.Accordingly, the same drawings and members will be described using thesame reference numerals and the same drawings.

Here, the tire case 17 according to this embodiment is formed of amixture including a polyamide-based thermoplastic elastomer (“UBESTAXPA9048X1” manufactured by Ube Industries, Ltd. of which the glasstransition temperature (Tg) of the hard segment (polyamide 12) is 40°C.) and polyphenylene ether (PPE) (“Xyron 200H” manufactured by AsahiKasei Chemicals Corporation, Tg: 210° C.) at a mass ratio (x+y:z) of thesoft segment (polyether: z) of the thermoplastic elastomer with respectto the total mass (x+y) of the hard segment (polyamide: x) and the resin(PPE: y) of 72:28. The mass ratio between the hard segment (polyamide12: x) and the resin (PPE: y) is 48:52.

The tire case 17 according to this embodiment is formed of a singlethermoplastic resin material (a polyamide-based thermoplasticelastomer+PPE), but the fifth aspect of the invention is not limited tothis configuration and the portions (such as the side portion 14, thecrown portion 16, and the bead portion 12) of the tire case 17 may beformed of thermoplastic resin materials having differentcharacteristics, similarly to typical conventional rubber pneumatictires. A reinforcing material (such as fiber, cord, unwoven fabric, andwoven fabric which are formed of a polymer material or metal) may beembedded in the tire case 17 (such as the bead portion 12, the sideportion 14, and the crown portion 16) to reinforce the tire case withthe reinforcing material.

The tire case 17 according to this embodiment is formed by bonding apair of tire case half parts (tire frame pieces) 17A formed of the resinmaterial including the polyamide-based thermoplastic elastomer and thePPE, to each other. The tire case 17A is formed by opposing annular tirecase half parts 17A, in which one bead portion 12, one side portion 14,and a half-width crown portion 16 are formed as a unified body byinjection molding or the like, having the same shape to each other andbonding both tire case half parts to each other at the tire equatorialplane portion. The tire case 17 is not limited to bonding two members,but may be formed by bonding three or more members. The others are thesame as the tire according to Embodiment 1-1 and the production methodthereof is also the same.

(Effects)

In the tire 10 according to this embodiment, since the tire case 17 isformed of the resin material including the polyamide-based thermoplasticelastomer and the PPE, the loss factor (tan δ) of the tire frame is keptlow and the elastic modulus is improved, compared with a case where onlythe polyamide-based thermoplastic elastomer is used. Accordingly, thetire 10 has superior heat resistance and has reduced rolling resistance.Since the tire 10 has a simpler structure than a conventional rubbertire, the weight is smaller. Accordingly, the tire 10 according to thisembodiment has excellent abrasion resistance and durability.

In the tire 10 according to this embodiment, since the reinforcing cord26 having rigidity higher than the resin material is wound on the outercircumferential surface of the crown portion 16 of the tire case 17formed of a resin material helically in the circumferential direction,puncture resistance, cutting resistance, and rigidity in thecircumferential direction of the tire 10 are improved. Since therigidity in the circumferential direction of the tire 10 is improved, itis possible to prevent creeping of the tire case 17 formed of athermoplastic resin material.

Since at least a part of the reinforcing cord 26 is embedded in theouter circumferential surface of the crown portion 16 of the tire case17 formed of the thermoplastic resin material and comes in close contactwith the resin material in a cross-sectional view (the cross-sectionshown in FIG. 1) taken along the axial direction of the tire case 17,the incorporation of air at the time of production is suppressed and themovement of the reinforcing cord 26 due to a force applied thereto atthe time of traveling is suppressed. Accordingly, it is possible tosuppress abrasion of the reinforcing cord 26, the tire case 17, and thetread 30 and thus to improve durability of the tire 10.

In this way, when the reinforcing cord layer 28 is formed to include theresin material, it is possible to reduce the difference in hardnessbetween the tire case 17 and the reinforcing cord layer 28 and thus tofurther closely contact and fix the reinforcing cord 26 with and to thetire case 17, compared with a case where the reinforcing cord 26 isfixed merely using the cushion rubber. Accordingly, it is possible toeffectively prevent the above-mentioned incorporation of air and thus toeffectively suppress the movement of the reinforcing cord member at thetime of traveling.

When the reinforcing cord 26 is a steel cord, the reinforcing cord 26can be easily separated and recovered from the resin material by heatingat the time of disposal of the tire and thus it is advantageous in viewof recyclability of the tire 10. The resin material usually has a lowerloss factor (tan δ) compared with a vulcanized rubber. Accordingly, whenthe reinforcing cord layer 28 contains a large amount of resin material,it is possible to enhance the rolling properties of the tire. The resinmaterial is more advantageous in that the resin material has highin-plane shear stiffness and has excellent steering stability andabrasion resistance at the time of traveling with the tire, comparedwith a vulcanized rubber.

As shown in FIG. 2, since the depth L of embedding of the reinforcingcord 26 is set to be equal to or more than ⅕ of the diameter D thereof,it is possible to effectively suppress the incorporation of air at thetime of production and to further suppress the movement of thereinforcing cord 26 due to a force applied thereto at the time oftraveling.

Since the tread 30 coming in contact with a road surface is formed of arubber material having abrasion resistance higher than the resinmaterial including the polyamide-based thermoplastic elastomer and thePPE, the abrasion resistance of the tire 10 is enhanced.

Since the annular bead core 18 formed of a metal material is embedded inthe bead portion 12, the tire case 17, that is, the tire 10, is stronglyretained in the rim 20, similarly to a conventional rubber pneumatictire.

Since the sealing layer 24 formed of a rubber material having highersealability than the resin material forming the tire case 17, isdisposed in the part of the bead portion 12 coming in contact with therim 20, the sealability between the tire 10 and the rim 20 is improved.Accordingly, compared with a case where the sealing is performed withthe rim 20 and the resin material forming the tire case 17, air leakagefrom the tire is further suppressed. By disposing the sealing layer 24,fittability onto a rim are also improved.

Although it is stated in the above embodiment that the reinforcing cord26 is heated to melt or soften the polyamide-based thermoplasticelastomer+PPE in the part coming in contact with the heated reinforcingcord 26, the fifth aspect of the invention is not limited to thisconfiguration, but the outer circumferential surface of the crownportion 16 in which the reinforcing cord 26 is to be embedded, may beheated using a hot air generating device, and then the reinforcing cord26 may be embedded in the crown portion 16, instead of heating thereinforcing cord 26.

Although the heat source of the cord heating device 59 includes theheater and the fan in Embodiment 5-1, the fifth aspect of the inventionis not limited to this configuration, but the reinforcing cord 26 may bedirectly heated with radiation heat (for example, infrared rays).

Although the melted or softened portion of the thermoplastic resinmaterial having the reinforcing cord 26 embedded therein is forciblycooled with the second roller 64 formed of metal in Embodiment 5-1, thefifth aspect of the invention is not limited to this configuration, butcold air may be directly applied to the melted or softened portion ofthe thermoplastic resin material to forcibly cool and solidify themelted or softened portion of the thermoplastic resin material.

Although the reinforcing cord 26 is heated in Embodiment 5-1, forexample, the outer circumference of the reinforcing cord 26 may becoated with the same thermoplastic resin material as the tire case 17.In this case, by heating the coated thermoplastic resin material alongwith the reinforcing cord 26 when the coated reinforcing cord is woundon the crown portion 16 of the tire case 17, it is possible toeffectively suppress the incorporation of air at the time of embeddingthe reinforcing cord in the crown portion 16.

The helical winding of the reinforcing cord 26 is easy in production,but it can also be considered that the reinforcing cord 26 is wounddiscontinuously in the width direction.

The tire 10 according to Embodiment 5-1 is a so-called tubeless tire inwhich an air chamber is formed between the tire 10 and the rim 20 byfitting the bead portion 12 to the rim 20. However, the fifth aspect ofthe invention is not limited to this configuration, but the tire mayhave a complete tube shape.

In the complete tube-like tire, for example, as shown in FIG. 4, threetire frames having an circular shape may be arranged in the tire widthdirection. FIG. 4 is a cross-sectional view of a tire according toanother embodiment. As shown in FIG. 4, a tire 86 includes a treadrubber layer 87, circular hollow tubes (tire frames) 88 formed of thesame resin material as described in Embodiment 5-1, a belt (reinforcingcord) 89, and a rim 90. Three tubes 88 are arranged side by side in thetire width direction of the tire 86. The tread rubber layer 87 in whichthe belt 89 is embedded is bonded to the outer peripheral portion of thetubes 88. The tubes 88 are fitted to the rim 90 having concave portionsengaging with the tubes 88. The tire 86 is not provided with a beadcore.

While the fifth aspect of the invention has been described withreference to the embodiments, the embodiments are only an example andcan be modified in various forms without departing from the conceptthereof. The scope of the fifth aspect of the invention is not limitedto the embodiments.

Embodiment 5-2

A method for producing a tire and Embodiment 5-2 of the tire of thefifth aspect of the invention will be described below with reference tothe accompanying drawings. Similarly to Embodiment 5-1, the tireaccording to this embodiment has substantially the same cross-sectionalshape as a typical conventional rubber pneumatic tire.

Here, the tire according to Embodiment 5-2 is the same as described inEmbodiment 1-2, except for the following points. Accordingly, the samedrawings and members will be described using the same reference numeralsand the same drawings.

In the tire according to Embodiment 5-2, similarly to Embodiment 5-1,the tire case 17 is formed of a mixture including a polyamide-basedthermoplastic elastomer (“UBESTA XPA9048X1” manufactured by UbeIndustries, Ltd. of which the glass transition temperature (Tg) of thehard segment (polyamide 12) is 40° C.) and polyphenylene ether (PPE)(“Xyron 200H” manufactured by Asahi Kasei Chemicals Corporation, Tg:210° C.), at a mass ratio (x+y:z) of the soft segment (polyether: z) ofthe thermoplastic elastomer with respect to the total mass (x+y) of thehard segment (polyamide: x) and the resin (PPE: y) of 72:28. The massratio between the hard segment (polyamide 12: x) and the resin (PPE: y)is 48:52. The other is the same as the tire according to Embodiment 1-2and the production method thereof is also the same.

(Effects)

In the tire 200 according to this embodiment, since the tire case 17 isformed of the resin material including the polyamide-based thermoplasticelastomer and the PPE, the loss factor (tan δ) of the tire frame is keptlow and the elastic modulus is improved, compared with a case where onlythe polyamide-based thermoplastic elastomer is used. Accordingly, thetire 10 has superior heat resistance and has reduced rolling resistance.Since the tire 200 has a simpler structure than a conventional rubbertire, the weight is smaller. Accordingly, the tire 200 according to thisembodiment has excellent abrasion resistance and durability.

In the method for producing a tire according to this embodiment, inunifying the tire case 17, the cushion rubber 29, and the tread rubber30A, the outer circumferential surface 17S of the tire case 17 has beensubjected to the roughening treatment and thus the adhesiveness (bondingproperties) is improved by the anchor effect. Since the resin materialforming the tire case 17 is indented due to the collision of theblasting abrasive, the wettability of the adhesive is improved.Accordingly, the adhesive is uniformly applied to the outercircumferential surface 17S of the tire case 17 and this state isretained, whereby it is possible to secure the bonding strength betweenthe tire case 17 and the cushion rubber 29.

Particularly, even when unevenness is formed on the outercircumferential surface 17S of the tire case 17, the blasting abrasiveis made to collide with the concave portions (the gaps 28A) to performthe roughening treatment on the peripheries (concave walls, concavebottoms) of the concave portions, whereby it is possible to secure thebonding strength between the tire case 17 and the cushion rubber 29.

On the other hand, since the cushion rubber 29 is stacked in theroughened region of the outer circumferential surface 17S of the tirecase 17, it is possible to effectively secure the bonding strengthbetween the tire case 17 and the cushion rubber.

When the cushion rubber 29 is vulcanized in the vulcanization step, thecushion rubber 29 flows in the roughened unevenness formed on the outercircumferential surface 17S of the tire case 17 through the rougheningtreatment. When the vulcanization is completed, an anchor effect isexhibited by the cushion rubber 29 flowing in the roughened unevenness,and the bonding strength between the tire case 17 and the cushion rubber29 is enhanced.

In the tire 200 produced by this method for producing a tire, thebonding strength between the tire case 17 and the cushion rubber 29 issecured. That is, the bonding strength between the tire case 17 and thetread 30 is secured through the cushion rubber 29. Accordingly, theabrasion of the outer circumferential surface 17S of the tire case 17 ofthe tire 200 from the cushion rubber 29 is suppressed.

Since the outer circumferential portion of the tire case 17 is formed ofthe reinforcing cord layer 28, puncture resistance and cuttingresistance are improved, compared with a case where the outercircumferential portion is formed of a member other than the reinforcingcord layer 28.

Since the coated cord member 26B is wound to form the reinforcing cordlayer 28, the rigidity in the circumferential direction of the tire 200is improved. Since the rigidity in the circumferential direction isimproved, creeping (a phenomenon in which the plastic deformation of thetire case 17 increases with the lapse of time under a constant stress)is suppressed and pressure resistance to air pressure from the inside inthe tire diameter direction is improved.

When the reinforcing cord layer 28 is formed to include the coated cordmember 26B, it is possible to reduce the difference in hardness betweenthe tire case 17 and the reinforcing cord layer 28 and thus to furtherclosely bring and fix the coated cord member 26B in contact with and tothe tire case 17, compared with a case where the reinforcing cord 26A isfixed merely using the cushion rubber 29. Accordingly, it is possible toeffectively prevent the above-mentioned incorporation of air and thus toeffectively suppress the movement of the reinforcing cord member at thetime of traveling.

When the reinforcing cord 26A is a steel cord, the cord member 26A canbe easily separated and recovered from the coated cord member 26B byheating at the time of disposal of the tire and thus it is advantageousin view of recyclability of the tire 200. The resin material has a lowerloss factor (tan δ) compared with a vulcanized rubber. Accordingly, whenthe reinforcing cord layer 28 contains a large amount of resin material,it is possible to enhance the rolling properties of the tire. The resinmaterial is more advantageous in that the resin material has highin-plane shear stiffness and has excellent steering stability andabrasion resistance at the time of traveling with the tire, comparedwith a vulcanized rubber.

Although unevenness is formed on the outer circumferential surface 17Sof the tire case 17 in this embodiment, the fifth aspect of theinvention is not limited to this configuration, but the outercircumferential surface 17S may be formed to be flat.

In the tire case 17, the coated cord member wound on and bonded to thecrown portion of the tire case may be covered with a coatingthermoplastic material to form a reinforcing cord layer. In this case,the melted or softened coating thermoplastic material may be ejectedonto the reinforcing cord layer 28 to form a coating layer. A weldingsheet may be heated into a melted or softened state without using anextruder and may be attached to the surface (the outer circumferentialsurface) of the reinforcing cord layer 28 to form a coating layer.

Although the case sub-frames (tire case half parts 17A) are bonded toform the tire case 17 in Embodiment 5-2, the fifth aspect of theinvention is not limited to this configuration, but the tire case 17 maybe formed as a unified body using a mold or the like.

The tire 200 according to Embodiment 5-2 is a so-called tubeless tire inwhich an air chamber is formed between the tire 200 and the rim 20 byfitting the bead portion 12 to the rim 20. However, the fifth aspect ofthe invention is not limited to this configuration, but the tire 200 mayhave, for example, a complete tube shape (for example, the shape shownin FIG. 4).

Although the cushion rubber 29 is interposed between the tire case 17and the tread 30 in Embodiment 5-2, the fifth aspect of the invention isnot limited to this configuration, but the cushion rubber 29 may not beinterposed therebetween.

Although the coated cord member 26B is helically wound on the crownportion 16 in Embodiment 5-2, the fifth aspect of the invention is notlimited to this configuration, but the coated cord member 26B may bewound thereon to be discontinuous in the width direction.

In Embodiment 5-2, a thermoplastic material is used as the coating resinmaterial 27 forming the coated cord member 26B, the coating resinmaterial 27 is melted or softened by heating, and the coated cord member26B is welded to the outer circumferential surface of the crown portion16. However, the fifth aspect of the invention is not limited to thisconfiguration, but the coated cord member 26B may be bonded to the outercircumferential surface of the crown portion 16 using an adhesive or thelike without heating the coating resin material 27.

A thermosetting resin may be used as the coating resin material 27forming the coated cord member 26B, and the coated cord member 26B maybe bonded to the outer circumferential surface of the crown portion 16using an adhesive or the like without heating the coated cord member26B.

A thermosetting resin may be used as the as the coating resin material27 forming the coated cord member 26B and the tire case 17 may be formedof a thermoplastic resin material. In this case, the coated cord member26B may be bonded to the outer circumferential surface of the crownportion 16 using an adhesive or the like, or a part of the tire case 17in which the coated cord member 26B is embedded may be heated to be in amelted or softened state and the coated cord member 26B may be welded tothe outer circumferential surface of the crown portion 16.

A thermoplastic resin may be used as the as the coating resin material27 forming the coated cord member 26B and the tire case 17 may be formedof a thermoplastic resin material. In this case, the coated cord member26B may be bonded to the outer circumferential surface of the crownportion 16 using an adhesive or the like, or a part of the tire case 17in which the coated cord member 26B is embedded may be heated into amelted or softened state, the coating resin material 27 is heated to bein a melted or softened state, and the coated cord member 26B may bewelded to the outer circumferential surface of the crown portion 16.When both the tire case 17 and the coated cord member 26B may be heatedto be in a melted or softened state, both are mixed with each other welland thus the bonding strength therebetween is improved. When athermoplastic resin material is used as the resin material forming thetire case 17 and a thermoplastic resin material is used as the coatingresin material 27 forming the coated cord member 26B, the same kind ofthermoplastic material, particularly, the same thermoplastic material,is preferably used.

The outer circumferential surface 17S of the tire case 17 may beactivated to enhance the hydrophilic property by performing a coronatreatment or a plasma treatment on the outer circumferential surface 17Shaving been subjected to the roughening treatment, and then an adhesivemay be applied thereto.

The sequence for producing the tire 200 is not limited to the sequencedescribed in Embodiment 5-2, but may be appropriately changed.

While the fifth aspect of the invention has been described withreference to the embodiments, the embodiments are only an example andcan be modified in various forms without departing from the conceptthereof. The scope of the fifth aspect of the invention is not limitedto the embodiments.

<<Sixth Aspect of the Invention>>

The tire of the invention according to a sixth aspect is a tire whichhas a circular tire frame formed of a thermoplastic resin material andin which a volume resistivity of the tire frame is in the range of1.0×10⁶ to 1.0×10¹⁰.

The tire of the invention according to the sixth aspect is excellent inantistatic performance by having the above-mentioned configuration.

A a tire frame which is a constituent of a tire of the inventionaccording to the sixth aspect will be described, and specificembodiments of a tire of the invention according to the sixth aspectwill be then described with reference to the accompanying drawings.

[Tire Frame]

The tire frame in the invention according to the sixth aspect is formedof a thermoplastic resin material and needs to have a volume resistivityin the range of 1.0×10⁶ to 1.0×10¹⁰. The volume resistivity of the tireframe is more preferably 1.0×10⁶ Ω·cm to 5.0×10⁹ Ω·cm and still morepreferably 5.0×10⁶ Ω·cm to 5.0×10⁹ Ω·cm.

The volume resistivity in the invention according to the sixth aspect isa value measured using a resistivity meter “HIRESTA UP MCP-HT450”manufactured by Mitsubishi Chemical Analytech Co., Ltd. on the basis ofJIS K6911:(1995).

In the invention according to the sixth aspect, the method ofcontrolling the volume resistivity of the tire frame is not particularlylimited, but a method of adding an antistatic material to the tire frameis preferable.

<Antistatic Material>

The antistatic material may be an inorganic material or an organicmaterial, as long as it can control the volume resistivity of the tireframe to be in the range of 1.0×10⁶ to 1.0×10¹⁰.

The antistatic material may be a solid or a liquid.

Examples of the antistatic material include conductive polymer materialssuch as polyaniline, polypyrrole, and polyacetylene; ion conductors suchas ammoniums salts such as perchlorate, chlorate, hydrochloride, borate,iodate, borohydrofluoride, sulfate, ethyl sulfate, carboxylate, andsulfonate of tetraethyl ammonium, tetrabutyl ammonium, dodecyl trimethylammonium, hexadecyl trimethyl ammonium, octadecyl trimethyl ammonium,benzyl trimethyl ammonium, and denatured aliphatic dimethyl ammonium;perchlorate, chlorate, hydrochloride, borate, iodate, borohydrofluoride,trifluoromehyl sulfate, sulfonate, and phosphoric acid esters ofalkaline metals such as lithium, sodium, potassium, calcium, andmagnesium, or alkaline earth metals; ionic liquids such asN,N-diethyl-N-methyl-N-(2-methoxyethyl)ammoniumtetrafluoroborate,1-ethyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazoliumdicyanamide, tetrabutylammonium bromide, and trihexyltetradecylphosphinium chloride; conductive carbons such as Ketien black andacetylene black; carbon black for rubber such as SAF, ISAF, HAF, FEF,GPF, SRF, FT, and MT; conductive carbon materials such asoxidation-treated carbon for ink, pyrolysis carbon, natural graphite,artificial graphite, vapor-grown carbon fiber (VGCF), and carbonnanotubes (CNT); conductive metal oxides such as tin oxide, titaniumoxide, and zinc oxide; and metals such as nickel, copper, silver, andgermanium.

Among these antistatic materials, ion conductors, carbon black, andionic liquids are preferred, and carbon black for rubber and ionconductors such as phosphoric acid ester are more preferred, and fromthe viewpoint of the compatibility of antistatic properties andsuppression of an increase in “tan”, ion conductors such as phosphoricacid ester are even more preferable.

Examples of the phosphoric acid ester-based ion conductor that can beapplied as an antistatic material include the compound represented bythe following general formula (a).

In general formula (a), R, R′, and R″ each independently represent ahydrogen atom or a monovalent substituent. Provided that, at least oneof R, R′, or R″ represents a monovalent substituent.

As the antistatic material, a commercially available product may beused, and examples thereof include Elenite series, for example, Elenite139, AB-100, 139A, A-73 R, K-320, and TS-897, manufactured by TAKAMATSUOIL&FAT CO., LTD.

The antistatic material contained in the tire skeleton form may besingular or in combination of two or more kinds thereof.

The content rate of the antistatic material is preferably from 1 mass %to 30 mass %, more preferably from 1 mass % to 20 mass %, and even morepreferably from 1 mass % to 10 mass %, with respect to the total mass ofthe thermoplastic resin material that forms a tire frame.

By incorporating the antistatic material as one of the componentscontaining the thermoplastic resin material that forms a tire frame, itcan be contained in the tire frame.

The component contained in the thermoplastic resin material may be athermoplastic resin or any of the components used in combination withthe thermoplastic resin.

In the case where a conductive polymer material is applied as theantistatic material, a tire frame may be formed, using a conductivethermoplastic resin as the conductive polymer material, by athermoplastic resin material including the conductive thermoplasticresin. Examples of the conductive thermoplastic resin include athermoplastic elastomer provided with conductivity.

When an ion conductor such as phosphoric acid ester is used as theantistatic material, it is possible to suppress an increase in rollingresistance while enhancing the antistatic performance of the tire. Whena conductive carbon material such as carbon black is used as theantistatic material, it is possible to exhibit a reinforcing effect ofimproving the tensile characteristics while enhancing the antistaticperformance of the tire.

This effect can solve the problem essential to the case where athermoplastic resin material is used as the material of the tire frameand it is thus possible to provide a safe tire with high performance.

The rolling resistance of the tire can be expressed using tan δ, whichis exhibited by the thermoplastic resin material forming the tire, as anindex. The loss factor (tan δ) of the thermoplastic resin material isconsidered to correspond to the magnitude of strain generated in thethermoplastic resin material when a stress is applied to thethermoplastic resin material. Therefore, the larger tan δ of thethermoplastic resin material forming the tire frame means that stain canbe more easily generated in the tire when a stress is applied to thetire due to friction between the tire and a road surface at the time oftraveling of a vehicle. As the tire generates larger strain, the rollingresistance of the tire becomes larger.

In this description, the “loss factor (tan δ)” is a value calculated bya ratio (G″/G′) between the storage shear elastic modulus (G′) and theloss shear elastic modulus (G″) at 30° C., 20 Hz, and 1% of shearingstrain and is a value representing a degree to which a material absorbsenergy (converts into heat) when the material is deformed (hereinafter,also referred to as “tan δ”). Since the larger tan δ causes absorptionof more energy, the rolling resistance of the tire increases andconsequently serves as a reason of degradation in fuel efficiency of thetire. The tan δ of the thermoplastic elastomer can be measured by theuse of a dynamic viscoelasticity measuring apparatus (Dynamic-MechanicalAnalysis: DMA).

(Thermoplastic Resin Material)

The tire frame in the invention according to the sixth aspect is formedof a thermoplastic resin material.

The “thermoplastic resin material” in the invention according to thesixth aspect means a material including at least a thermoplastic resin,and the thermoplastic resin material may include components other thanthe thermoplastic resin.

The “thermoplastic resin” in the invention according to the sixth aspectdoes not include a vulcanized rubber such as conventional natural rubberor synthetic rubber.

<Thermoplastic Elastomer>

The thermoplastic resin material in the invention according to the sixthaspect includes a thermoplastic elastomer.

The “thermoplastic elastomer” in the invention according to the sixthaspect is a kind of thermoplastic resin as described above, and means athermoplastic resin including a copolymer having a polymer constitutinga crystalline hard segment with a high melting point or a hard segmentwith a high cohesive force and a polymer constituting a non-crystallinesoft segment with a low glass transition temperature in a molecule.

Examples of the thermoplastic elastomer which can be used in theinvention according to the sixth aspect include a polyamide-basedthermoplastic elastomer (TPA), a polyester-based thermoplastic elastomer(TPC), a polyolefin-based thermoplastic elastomer (TPO), apolystyrene-based thermoplastic elastomer (TPS), a polyurethane-basedthermoplastic elastomer (TPU), a thermoplastic cross-linked rubber(TPV), and other thermoplastic elastomers (TPZ), which are defined inJIS K6418:2007.

—Polyamide-Based Thermoplastic Elastomer—

The polyimide-based thermoplastic elastomer is a copolymer including apolymer constituting a crystalline hard segment with a high meltingpoint and a polymer constituting a non-crystalline soft segment with alow glass transition temperature, and means a copolymer in which themain chain of the polymer constituting the hard segment has an amidebond (—CONH—). The “polyamide-based thermoplastic elastomer” in thisembodiment may be the same polyamide-based thermoplastic elastomer asdescribed in the the first aspect of the invention.

—Polyester-Based Thermoplastic Elastomer—

Examples of the polyester-based thermoplastic elastomer includematerials in which at least polyester constitutes a crystalline hardsegment with a high melting point and another polymer (such as polyesterand polyether) constitutes a non-crystalline soft segment with a lowglass transition temperature. The “polyester-based thermoplasticelastomer” in this embodiment may be the same as described in the secondaspect of the invention.

—Polystyrene-Based Thermoplastic Elastomer—

Examples of the polystyrene-based thermoplastic elastomer includematerials in which at least polystyrene constitutes a hard segment andanother polymer (such as polybutadiene, polyisoprene, polyethylene,hydrogenated polybutadiene, and hydrogenated polyisoprene) constitutes anon-crystalline soft segment with a low glass transition temperature.The “polystyrene-based thermoplastic elastomer” in this embodiment maybe the same as described in the second aspect of the invention.

—Polyurethane-Based Thermoplastic Elastomer—

Examples of the polyurethane-based thermoplastic elastomer includematerials in which at least polyurethane constitutes a hard segmentforming a pseudo-crosslink through physical agglomeration and anotherpolymer constitutes a non-crystalline soft segment with a low glasstransition temperature. The “polyurethane-based thermoplastic elastomer”in this embodiment may be the same as described in the second aspect ofthe invention.

—Polyolefin-Based Thermoplastic Elastomer—

Examples of the polyolefin-based thermoplastic elastomer includematerials in which at least polyolefin constitutes a crystalline hardsegment with a high melting point and another polymer (such as thepolyolefin described above, another polyolefin, and a polyvinylcompound) constitutes a non-crystalline soft segment with a low glasstransition temperature. The “polyolefin-based thermoplastic elastomer”in this embodiment may be the same as described in the second aspect ofthe invention.

An acid-denatured elastomer formed by acid denaturation of athermoplastic elastomer may be used as the thermoplastic elastomer.

An example of the “acid-denatured elastomer formed by acid denaturationof a thermoplastic elastomer” is an acid-denatured elastomer in which anacid group is introduced into the thermoplastic elastomer using acompound having an acid group. Examples of the compound having an acidgroup used to acid-modify the thermoplastic elastomer includeunsaturated compounds having an acid group such as a carboxylic group, asulfric acid group, and a phosphoric acid group. As the unsaturatedcompound having an acid group, an unsaturated compound having acarboxylic group which is a weak acid group can be preferably used fromthe viewpoint of suppressing of degradation of the thermoplasticelastomer, and examples thereof include an acrylic acid, a methacrylicacid, an itaconic acid, a crotonic acid, an isocrotonic acid, and amaleic acid.

An example of the method of acid denaturation of the thermoplasticelastomer is a method of bonding the unsaturated bonding site of theunsaturated carboxylic acid to the olefin-based thermoplastic elastomeror the polystyrene-based thermoplastic elastomer through graftpolymerization or the like.

The thermoplastic resin material may include two or more kinds ofthermoplastic elastomers, but preferably includes one kind ofthermoplastic elastomer from the viewpoint of controlling the tireperformance of the tire formed using the thermoplastic resin material.

Among the above-mentioned thermoplastic elastomers, the polyamide-basedthermoplastic elastomer may be preferably used from the viewpoint ofexcellent tensile modulus of elasticity, tensile strength, and fracturestrain and weldability at a low temperature. From the viewpoint ofexcellent tensile modulus of elasticity, tensile strength, and fracturestrain, high heat resistance, and a wide temperature setting range, thepolyester-based thermoplastic elastomer may also be preferably used.Among these, the polyamide-based thermoplastic elastomer may beparticularly preferably used as the thermoplastic elastomer in theinvention according to the sixth aspect.

—Physical Properties of Thermoplastic Elastomer—

The tensile modulus of elasticity, which is defined in JIS K7113:1995,of the thermoplastic resin material in the invention according to thesixth aspect is preferably 100 to 1000 MPa, more preferably 100 to 800MPa, and still more preferably 100 to 700 MPa. When the tensile modulusof elasticity of the thermoplastic resin material is 100 to 1000 MPa, itis possible to efficiently fit onto a rim while maintaining the shape ofa tire frame. The elastic modulus is a value obtained by measuring adumbbell-shaped sample piece (sample piece No. 5) defined in JISK6251:1993 at a pulling rate of 200 mm/min by the use of ShimadzuAutograph AGS-J (5 kN) manufactured by Shimadzu Corporation.

The tensile yield strength, which is defined in JIS K7113:1995, of thethermoplastic resin material in the invention according to the sixthaspect is preferably equal to or more than 5 MPa, more preferably 5 to20 MPa, and still more preferably 5 to 17 MPa. When the tensile yieldstrength of the thermoplastic resin material is equal to or more than 5MPa, it is possible to resist deformation due to a load applied to atire during traveling or the like.

The tensile yield elongation, which is defined in JIS K7113:1995, of thethermoplastic resin material in the invention according to the sixthaspect is preferably equal to or more than 10%, more preferably 10% to70%, and still more preferably 15% to 60%. When the tensile yieldelongation of the thermoplastic resin material is equal to or more than10%, it is possible to increase an elastic region and to improvefittability onto a rim.

The tensile fracture elongation, which is defined in JIS K7113:1995, ofthe thermoplastic resin material in the invention according to the sixthaspect is preferably equal to or more than 50%, more preferably equal toor more than 100%, still more preferably equal to or more than 150%, andstill more preferably equal to or more than 200%. When the tensilefracture elongation of the thermoplastic resin material is equal to ormore than 50%, it is possible to improve fittability onto a rim and tosuppress fracture due to collision.

The deflection temperature under load (under a load of 0.45 MPa), whichis defined in ISO 75-2 or ASTM D648, of the thermoplastic resin materialin the invention according to the sixth aspect is preferably equal to orhigher than 50° C., more preferably 50° C. to 150° C., and still morepreferably 50° C. to 130° C. When the deflection temperature under loadof the thermoplastic resin material is equal to or higher than 50° C.,it is possible to suppress deformation of a tire frame in avulcanization step of a tread or the like.

The content of the thermoplastic elastomer in the thermoplastic resinmaterial in the invention according to the sixth aspect is preferably 40mass % to 95 mass % and more preferable 50 mass % to 90 mass %, withrespect to the total mass of the thermoplastic resin material, from theviewpoint of sufficient exhibition of performance of the thermoplasticelastomer.

The thermoplastic resin material in the invention according to the sixthaspect may optionally contain various additives other than the specificneedle-shaped crystal grains in addition to the antistatic material aslong as they do not impair the effect of the sixth aspect of theinvention. Examples of the additives include a filler, an anti-agingagent, oil, a plasticizer, a colorant, a weather resistant agent, and areinforcing agent.

The thermoplastic resin material in the sixth aspect of the inventioncan be prepared as a mixture, for example, by mixing the thermoplasticelastomer, the antistatic material, and various additives which areoptionally used, and melting and kneading the resultant. Thethermoplastic resin material can be used optionally in a pellet shape.

The tire of the sixth aspect of the invention includes a circular tireframe (hereinafter, appropriately also referred to as a “tire case”)formed of the above-mentioned thermoplastic resin material. The tireframe may be formed by molding the thermoplastic resin material into aunified body using various molding methods or may be formed by forming apair of tire case half parts (tire frame pieces) using various moldingmethods and then bonding the tire case half parts. From the viewpoint ofproductivity, it is preferable that the tire frame be formed by bondinga pair of half case cases.

[Reinforcing Cord Layer]

The tire of the sixth aspect of the invention may have a reinforcingcord member which is wound on the outer circumferential portion of thetire frame in the circumferential direction to form a reinforcing cordlayer.

The [Resin Material of Reinforcing Cord Layer] in the sixth aspect ofthe invention may be the same as the [Resin Material of Reinforcing CordLayer] in the first aspect of the invention.

Specific examples of the tire of the sixth aspect of the invention willbe described in more detail below with reference to Embodiments 6-1 and6-2.

Embodiment 6-1

A tire according to Embodiment 6-1 of the tire of the sixth aspect ofthe invention will be described below with reference to the accompanyingdrawings. Here, the tire according to Embodiment 6-1 is the same asdescribed in Embodiment 1-1, except for the following points.Accordingly, the same drawings and members will be described using thesame reference numerals and the same drawings.

The tire case 17 according to this embodiment is formed of athermoplastic resin material which is a mixture of a polyamide-basedthermoplastic elastomer (“UBESTA XPA9055X1” manufactured by UbeIndustries, Ltd.) and an antistatic material (“ELENITE AB-100”manufactured by Takamatsu Oil & Fat Co., Ltd.). The volume resistivityof the tire case 17 is 2.1×10⁹ Ω·cm.

The tire case 17 according to this embodiment is formed of athermoplastic resin material including a single thermoplastic elastomerand the antistatic material, but the sixth aspect of the invention isnot limited to this configuration and the portions (such as the sideportion 14, the crown portion 16, and the bead portion 12) of the tirecase 17 may be formed of thermoplastic resin materials having differentcharacteristics, similarly to typical conventional rubber pneumatictires. A reinforcing material (such as fiber, cord, unwoven fabric, andwoven fabric which are formed of a polymer material or metal) may beembedded in the tire case 17 (such as the bead portion 12, the sideportion 14, and the crown portion 16) to reinforce the tire case 17 withthe reinforcing material. The other is the same as the tire of accordingto Embodiment 1-1 and the production method thereof is also the same.

(Effects)

In the tire 10 according to this embodiment, since the tire case 17 isformed of the thermoplastic resin material including the polyamide-basedthermoplastic elastomer and the phosphoric acid ester-based ionconductor as the antistatic material, the antistatic performance isexcellent and the low tan δ characteristics (low loss or lowheat-emission) are superior, compared with a case where a thermoplasticresin material including only the thermoplastic elastomer is used.Accordingly, the tire 10 exhibits excellent antistatic performance andhas superior rolling resistance. Since the tire 10 has a simplerstructure than a conventional rubber tire, the weight is smaller.Accordingly, the tire 10 according to this embodiment has excellentabrasion resistance and durability.

In the tire 10 according to this embodiment, since the reinforcing cord26 having rigidity higher than the resin material is wound on the outercircumferential surface of the crown portion 16 of the tire case 17formed of a thermoplastic resin material helically in thecircumferential direction, puncture resistance, cutting resistance, andrigidity in the circumferential direction are improved. Since therigidity in the circumferential direction of the tire 10 is improved, itis possible to prevent creeping of the tire case 17 formed of athermoplastic resin material.

Since at least a part of the reinforcing cord 26 is embedded in theouter circumferential surface of the crown portion 16 of the tire case17 formed of the thermoplastic resin material and comes in close contactwith the resin material in a cross-sectional view (the cross-sectionshown in FIG. 1) taken along the axial direction of the tire case 17,the incorporation of air at the time of production is suppressed and themovement of the reinforcing cord 26 due to a force applied thereto atthe time of traveling is suppressed. Accordingly, it is possible tosuppress abrasion of the reinforcing cord 26, the tire case 17, and thetread 30 and thus to improve durability of the tire 10.

In this way, when the reinforcing cord layer 28 is formed to include theresin material, it is possible to reduce the difference in hardnessbetween the tire case 17 and the reinforcing cord layer 28 and thus tofurther closely contact and fix the reinforcing cord 26 with and to thetire case 17, compared with a case where the reinforcing cord 26 isfixed merely using the cushion rubber. Accordingly, it is possible toeffectively prevent the above-mentioned incorporation of air and thus toeffectively suppress the movement of the reinforcing cord member at thetime of traveling.

When the reinforcing cord 26 is a steel cord, the reinforcing cord 26can be easily separated and recovered from the resin material by heatingat the time of disposal of the tire and thus it is advantageous in viewof recyclability of the tire 10. The resin material usually has a lowerloss factor (tan δ) compared with a vulcanized rubber. Accordingly, whenthe reinforcing cord layer 28 contains a large amount of resin material,it is possible to enhance the rolling properties of the tire. The resinmaterial is more advantageous in that the resin material has highin-plane shear stiffness and has excellent steering stability andabrasion resistance at the time of traveling with the tire, comparedwith a vulcanized rubber.

As shown in FIG. 2, since the depth L of embedding of the reinforcingcord 26 is set to be equal to or more than ⅕ of the diameter D thereof,it is possible to effectively suppress the incorporation of air at thetime of production and to further suppress the movement of thereinforcing cord 26 due to a force applied thereto at the time oftraveling.

Since the tread 30 coming in contact with a road surface is formed of arubber material having abrasion resistance higher than the resinmaterial including first and second thermoplastic elastomers, theabrasion resistance of the tire 10 is enhanced.

Since the annular bead core 18 formed of a metal material is embedded inthe bead portion 12, the tire case 17, that is, the tire 10, is stronglyretained in the rim 20, similarly to a conventional rubber pneumatictire.

Since the sealing layer 24 formed of a rubber material having highersealability than the resin material forming the tire case 17 is disposedin the part of the bead portion 12 coming in contact with the rim 20,the sealability between the tire 10 and the rim 20 is improved.Accordingly, compared with a case where the sealing is performed withthe rim 20 and the resin material forming the tire case 17, air leakagefrom the tire is further suppressed. By disposing the sealing layer 24,fittability onto a rim are also improved.

Although it is stated in Embodiment 6-1 that the reinforcing cord 26 isheated to melt or soften the thermoplastic resin material in the partcoming in contact with the heated reinforcing cord 26, the sixth aspectof the invention is not limited to this configuration, but the outercircumferential surface of the crown portion 16 where the reinforcingcord 26 is to be embedded therein may be heated using a hot airgenerating device, and then the reinforcing cord 26 may be embedded inthe crown portion 16, instead of heating the reinforcing cord 26.

Although the heater and the fan are adopted as the heat source of thecord heating device 59 in Embodiment 6-1, the sixth aspect of theinvention is not limited to this configuration, but the reinforcing cord26 may be directly heated with radiation heat (for example, infraredrays).

Although the melted or softened portion of the thermoplastic resinmaterial having the reinforcing cord 26 embedded therein is forciblycooled with the second roller 64 formed of metal in Embodiment 6-1, thesixth aspect of the invention is not limited to this configuration, butcold air may be directly applied to the melted or softened portion ofthe thermoplastic resin material to forcibly cool and solidify themelted or softened portion of the thermoplastic resin material.

Although the reinforcing cord 26 is heated in Embodiment 6-1, forexample, the outer circumference of the reinforcing cord 26 may becoated with the same thermoplastic resin material as the tire case 17.In this case, by heating the coated thermoplastic resin material alongwith the reinforcing cord 26 when the coated reinforcing cord is woundon the crown portion 16 of the tire case 17, it is possible toeffectively suppress the incorporation of air at the time of embeddingthe reinforcing cord in the crown portion 16.

The helical winding of the reinforcing cord 26 is easy in production,but it can also be considered that the reinforcing cord 26 is wounddiscontinuously in the width direction.

The tire 10 according to Embodiment 6-1 is a so-called tubeless tire inwhich an air chamber is formed between the tire 10 and the rim 20 byfitting the bead portion 12 to the rim 20. However, the sixth aspect ofthe invention is not limited to this configuration, but the tire mayhave a complete tube shape.

In the complete tube-like tire, for example, as shown in FIG. 4, threetire frames having a circular shape may be arranged in the tire widthdirection. FIG. 4 is a cross-sectional view of a tire according toanother embodiment. As shown in FIG. 4, a tire 86 includes a treadrubber layer 87, circular hollow tubes (tire frames) formed of the sameresin material as described in Embodiment 6-1, a belt (reinforcing cord)89, and a rim 90. Three tubes 88 are arranged side by side in the tirewidth direction of the tire 86. The tread rubber layer 87 in which thebelt 89 is embedded is bonded to the outer peripheral portion of thetubes 88. The tubes 88 are fitted to the rim 90 having concave portionsengaging with the tubes 88. The tire 86 is not provided with a beadcore.

While the sixth aspect of the invention has been described withreference to the embodiments, the embodiments are only an example andcan be modified in various forms without departing from the conceptthereof. The scope of the sixth aspect of the invention is not limitedto the embodiments.

Embodiment 6-2

An Embodiment 6-2 of the tire of the sixth aspect of the invention willbe described below with reference to the accompanying drawings.

Here, the tire according to Embodiment 6-2 is the same as described inEmbodiment 1-2, except for the following points. Accordingly, the samedrawings and members will be described using the same reference numeralsand the same drawings.

Similarly to Embodiment 6-1, the tire case 17 of the tire according toEmbodiment 6-2 is formed of a thermoplastic resin material which is amixture of a polyamide-based thermoplastic elastomer (“UBESTA XPA9055X1”manufactured by Ube Industries, Ltd.) and an antistatic material(“ELENITE AB-100” manufactured by Takamatsu Oil & Fat Co., Ltd.). Thevolume resistivity of the tire case 17 is 2.1×10⁹ Ω·cm. The other is thesame as the tire according to Embodiment 1-2 and the production methodthereof is also the same.

(Effects)

In the tire 200 according to this embodiment, since the tire case 17 isformed of the thermoplastic resin material including the polyamide-basedthermoplastic elastomer and the phosphoric acid ester-based ionconductor as the antistatic material, the antistatic performance isexcellent and the low tan δ characteristics (low loss or lowheat-emission) are superior, compared with a case where a thermoplasticresin material including only the thermoplastic elastomer is used.Accordingly, the tire 200 exhibits excellent antistatic performance andhas superior low tan δ characteristics (low loss or low heat-emission).Since the tire 200 has a simpler structure than a conventional rubbertire, the weight is smaller. Accordingly, the tire 200 according to thisembodiment has excellent abrasion resistance and durability.

In the method for producing a tire according to this embodiment, inunifying the tire case 17, the cushion rubber 29, and the tread rubber30A, the outer circumferential surface 17S of the tire case 17 has beensubjected to the roughening treatment and thus the adhesiveness (bondingproperties) is improved by the anchor effect. Since the resin materialforming the tire case 17 is indented due to the collision of theblasting abrasive, the wettability of the adhesive is improved.Accordingly, the adhesive is uniformly applied to the outercircumferential surface 17S of the tire case 17 and this state isretained, whereby it is possible to secure the bonding strength betweenthe tire case 17 and the cushion rubber 29.

Particularly, even when unevenness is formed on the outercircumferential surface 17S of the tire case 17, the blasting abrasiveis made to collide with the concave portions (the gaps 28A) to performthe roughening treatment on the peripheries (concave walls, concavebottoms) of the concave portions, whereby it is possible to secure thebonding strength between the tire case 17 and the cushion rubber 29.

On the other hand, since the cushion rubber 29 is stacked in theroughened region of the outer circumferential surface 17S of the tirecase 17, it is possible to effectively secure the bonding strengthbetween the tire case 17 and the cushion rubber.

When the cushion rubber 29 is vulcanized in the vulcanization step, thecushion rubber 29 flows in the roughened unevenness formed on the outercircumferential surface 17S of the tire case 17 through the rougheningtreatment. When the vulcanization is completed, an anchor effect isexhibited by the cushion rubber 29 flowing in the roughened unevenness,and the bonding strength between the tire case 17 and the cushion rubber29 is enhanced.

In the tire 200 produced by this method for producing a tire, thebonding strength between the tire case 17 and the cushion rubber 29 issecured. That is, the bonding strength between the tire case 17 and thetread 30 is secured through the cushion rubber 29. Accordingly, theabrasion of the outer circumferential surface 17S of the tire case 17 ofthe tire 200 from the cushion rubber 29 is suppressed.

Since the outer circumferential portion of the tire case 17 is formed ofthe reinforcing cord layer 28, puncture resistance and cuttingresistance are improved, compared with a case where the outercircumferential portion is formed of a member other than the reinforcingcord layer 28.

Since the coated cord member 26B is wound to form the reinforcing cordlayer 28, the rigidity in the circumferential direction of the tire 200is improved. Since the rigidity in the circumferential direction isimproved, creeping of the tire case 17 (a phenomenon in which theplastic deformation of the tire case 17 increases with the lapse of timeunder a constant stress) is suppressed and pressure resistance to airpressure from the inside in the tire diameter direction is improved.

When the reinforcing cord layer 28 is formed to include the coated cordmember 26B, it is possible to reduce the difference in hardness betweenthe tire case 17 and the reinforcing cord layer 28 and thus to furtherclosely bring and fix the coated cord member 26B in contact with and tothe tire case 17, compared with a case where the reinforcing cord 26A isfixed merely using the cushion rubber 29. Accordingly, it is possible toeffectively prevent the above-mentioned incorporation of air and thus toeffectively suppress the movement of the reinforcing cord member at thetime of traveling.

When the reinforcing cord 26A is a steel cord, the cord member 26A canbe easily separated and recovered from the coated cord member 26B byheating at the time of disposal of the tire and thus it is advantageousin view of recyclability of the tire 200. The resin material has a lowerloss factor (tan d) compared with a vulcanized rubber. Accordingly, whenthe reinforcing cord layer 28 contains a large amount of resin material,it is possible to enhance the rolling properties of the tire. The resinmaterial is more advantageous in that the resin material has highin-plane shear stiffness and has excellent steering stability andabrasion resistance at the time of traveling with the tire, comparedwith a vulcanized rubber.

Although unevenness is formed on the outer circumferential surface 17Sof the tire case 17 in this embodiment, the sixth aspect of theinvention is not limited to this configuration, but the outercircumferential surface 17S may be formed to be flat.

In the tire case 17, the coated cord member wound on and bonded to thecrown portion of the tire case may be covered with a coatingthermoplastic material to form a reinforcing cord layer. In this case,the melted or softened coating thermoplastic material may be ejectedonto the reinforcing cord layer 28 to form a coating layer. A weldingsheet may be heated into a melted or softened state without using anextruder and may be attached to the surface (the outer circumferentialsurface) of the reinforcing cord layer 28 to form a coating layer.

Although the tire case half parts 17A are bonded to form the tire case17 in Embodiment 6-2, the sixth aspect of the invention is not limitedto this configuration, but the tire case 17 may be formed as a unifiedbody using a mold or the like.

The tire 200 according to Embodiment 6-2 is a so-called tubeless tire inwhich an air chamber is formed between the tire 200 and the rim 20 byfitting the bead portion 12 to the rim 20. However, the sixth aspect ofthe invention is not limited to this configuration, but the tire 200 mayhave, for example, a complete tube shape (for example, the shape shownin FIG. 4).

Although the cushion rubber 29 is interposed between the tire case 17and the tread 30 in Embodiment 6-2, the sixth aspect of the invention isnot limited to this configuration, but the cushion rubber 29 may not beinterposed therebetween.

Although the coated cord member 26B is helically wound on the crownportion 16 in Embodiment 6-2, the sixth aspect of the invention is notlimited to this configuration, but the coated cord member 26B may bewound thereon to be discontinuous in the width direction.

In Embodiment 6-2, a thermoplastic material is used as the coating resinmaterial 27 forming the coated cord member 26B, the coating resinmaterial 27 is melted or softened by heating, and the coated cord member26B is welded to the outer circumferential surface of the crown portion16. However, the sixth aspect of the invention is not limited to thisconfiguration, but the coated cord member 26B may be bonded to the outercircumferential surface of the crown portion 16 using an adhesive or thelike without heating the coating resin material 27.

A thermosetting resin may be used as the coating resin material 27forming the coated cord member 26B, and the coated cord member may bebonded to the outer circumferential surface of the crown portion 16using an adhesive or the like without heating the coated cord member26B.

A thermosetting resin may be used as the as the coating resin material27 forming the coated cord member 26B and the tire case 17 may be formedof a thermoplastic resin material. In this case, the coated cord member26B may be bonded to the outer circumferential surface of the crownportion 16 using an adhesive or the like, or a part of the tire case 17in which the coated cord member 26B is embedded may be heated to be in amelted or softened state and the coated cord member 26B may be welded tothe outer circumferential surface of the crown portion 16.

A thermoplastic resin may be used as the as the coating resin material27 forming the coated cord member 26B and the tire case 17 may be formedof a thermoplastic resin material. In this case, the coated cord member26B may be bonded to the outer circumferential surface of the crownportion 16 using an adhesive or the like, or a part of the tire case 17in which the coated cord member 26B is embedded may be heated into amelted or softened state, the coating resin material 27 is heated to bein a melted or softened state, and the coated cord member 26B may bewelded to the outer circumferential surface of the crown portion 16.When both the tire case 17 and the coated cord member 26B may be heatedto be in a melted or softened state, both are mixed with each other welland thus the bonding strength therebetween is improved. When athermoplastic resin material is used as the resin material forming thetire case 17 and a thermoplastic resin material is used as the coatingresin material 27 forming the coated cord member 26B, the same kind ofthermoplastic material, particularly, the same thermoplastic material,is preferably used.

The outer circumferential surface 17S of the tire case 17 may beactivated to enhance the hydrophilic property by performing a coronaprocess or a plasma process on the outer circumferential surface 17Shaving been subjected to the roughening treatment, and then an adhesivemay be applied thereto.

The sequence for producing the tire 200 is not limited to the sequencedescribed in Embodiment 6-2, but may be appropriately changed.

While the sixth aspect of the invention has been described withreference to the embodiments, the embodiments are only an example andcan be modified in various forms without departing from the conceptthereof. The scope of the sixth aspect of the invention is not limitedto the embodiments.

<<Seventh Aspect of the Invention>>

Next, a thermoplastic resin material as a component of the tire frameaccording to a seventh aspect of the invention will be described, and,subsequently, a specific embodiment of the tire of the inventionaccording to the seventh aspect will be described using the drawings.

[Thermoplastic Resin Material]

The tire according to the seventh aspect of the invention includes acircular tire frame formed of a thermoplastic resin material, in whichthe thermoplastic resin material includes a thermoplastic elastomerincluding a hard segment and a soft segment in a molecule thereof, and aresin of the same kind as the hard segment, which is other than thethermoplastic elastomer.

It is possible to make it difficult for the rolling resistance of thetire to increase even when the elastic modulus of the thermoplasticresin material is large by applying a combination of a thermoplasticelastomer and a resin of the same kind as the hard segment included inthe thermoplastic elastomer, which is other than the thermoplasticelastomer, (the specific resin according to the seventh aspect of theinvention) as the thermoplastic resin material as a component of thecircular tire frame that forms the tire.

Hereinafter, the thermoplastic elastomer and the specific resinaccording to the seventh aspect of the invention will be described.

[Thermoplastic Elastomer]

The “thermoplastic elastomer” refers to a thermoplastic resin materialincluding a hard segment and a soft segment in the molecule as describedabove, and, in detail, to a thermoplastic resin material which is anelastic macromolecular compound and is formed of a copolymer having apolymer constituting a hard segment that is crystalline and has a highmelting point, and a polymer constituting a soft segment that isnon-crystalline and has a low glass transition temperature. Meanwhile,the thermoplastic elastomer does not include vulcanized rubber, such asnatural rubber or synthetic rubber of the related art.

Examples of the thermoplastic elastomer include polyamide-basedthermoplastic elastomers, polyolefin-based thermoplastic elastomers,polystyrene-based thermoplastic elastomers, polyester-basedthermoplastic elastomers and the like.

(Polyamide-Based Thermoplastic Elastomer)

The “polyamide-based thermoplastic elastomer” is an elasticmacromolecular compound, and refers to an elastomer that is athermoplastic resin material formed of a copolymer having a polymerconstituting a hard segment that is crystalline and has a high meltingpoint, and a polymer constituting a soft segment that is amorphous andhas a low glass transition temperature, and has an amid bond (—CONH—) inthe main chain of the polymer constituting the hard segment.

Examples of crystalline polyamide constituting the hard segment includealiphatic polyamides, such as polycaproamide (nylon-6),poly-ω-aminoheptanoic acid (nylon-7), poly-ω-aminononanoic acid(nylon-9), polyundecaneamide (nylon-11), polylauryl lactam (nylon-12),polyethylene diamine adipamide (nylon-2,6), polytetramethylene adipamide(nylon-4,6), polyhexamethylene adipamide (nylon-6,6), polyhexamethylenesebacamide (nylon-6,10), polyhexamethylene dodecamide (nylon-6,12),polyoctamethylene adipamide (nylon-8,6) and polydecamethylene adipamide(nylon-10,8); crystalline aromatic polyamides obtained through apolycondensation reaction between an aromatic diamine, such asmeta-xylene diamine or para-xylene diamine, and a dicarboxylic acid,such as adipic acid, suberic acid, sebacic acid, cyclohexanedicarboxylic acid, terephthalic acid or isophthalic acid, or aderivative thereof; and the like.

Among the above, nylon-6, nylon-6,6, nylon-12 and the like arepreferable, and nylon-12 is more preferable. As the “polyamide-basedthermoplastic elastomer” in the present embodiment, the samepolyamide-based thermoplastic elastomer as in the invention according tothe above first aspect can be used.

(Polyolefin-Based Thermoplastic Elastomer)

The “polyolefin-based thermoplastic elastomer” is an elasticmacromolecular compound, and refers to a thermoplastic resin materialformed of a copolymer having a polymer constituting a hard segment thatis crystalline and has a high melting point, and a polymer constitutinga soft segment that is non-crystalline and has a low glass transitiontemperature. The “polyolefin-based thermoplastic elastomer” in theembodiment is the same as in the above second aspect of the invention.

(Polystyrene-Based Thermoplastic Elastomer)

The “polystyrene-based thermoplastic elastomer” is an elasticmacromolecular compound, and refers to a thermoplastic resin materialformed of a copolymer having a polymer constituting the hard segment,and a polymer constituting a soft segment that is non-crystalline andhas a low glass transition temperature, in which the polymerconstituting the hard segment includes polystyrene and a polystyrenederivative. The “polystyrene-based thermoplastic elastomer” in theembodiment is the same as in the above second aspect of the invention.

(Polyester-Based Thermoplastic Elastomer)

The polyester-based thermoplastic elastomer according to the seventhaspect of the invention is an elastic macromolecular compound, andrefers to a thermoplastic resin material formed of a copolymer having apolymer constituting a hard segment that is crystalline and has a highmelting point, and a polymer constituting a soft segment that isnon-crystalline and has a low glass transition temperature, in which apolyester resin is included as the polymer constituting the hardsegment. The “polyester-based thermoplastic elastomer” in the embodimentis the same as in the above second aspect of the invention.

The thermoplastic resin material may include two or more thermoplasticelastomers, but the thermoplastic resin material preferably includes onethermoplastic elastomer from the viewpoint of controlling the tireperformances of a tire formed using the thermoplastic resin material.

Among the thermoplastic elastomers described above, the polyamide-basedthermoplastic elastomer is preferable since the polyamide-basedthermoplastic elastomer has thermal resistance and is excellent in termof tensile modulus of elasticity, tensile strength and fracture strain.

[Resin of the Same Kind (Specific Resin According to the Seventh Aspectof the Invention)]

The thermoplastic resin includes a resin of the same kind as the hardsegment included in the thermoplastic elastomer, which is other than thethermoplastic elastomer, (the specific resin according to the seventhaspect of the invention).

The “resin of the same kind as the hard segment” included in thethermoplastic elastomer refers to a resin having a skeleton which iscommon to the skeleton constituting the main chain of the hard segmentincluded in the thermoplastic elastomer, and the resin according to theseventh aspect of the invention refers to a thermoplastic orthermosetting resin, but does not encompass vulcanized rubber, such asnatural rubber or synthetic rubber of the related art.

Specifically, when the thermoplastic elastomer included in thethermoplastic resin material is a polyamide-based thermoplasticelastomer, a polyamide-based resin may be used as the specific resinaccording to the seventh aspect of the invention; when the thermoplasticelastomer is a polyolefin-based thermoplastic elastomer, apolyolefin-based resin may be used as the specific resin according tothe seventh aspect of the invention; and when the thermoplasticelastomer is a polystyrene-based thermoplastic elastomer, apolystyrene-based resin may be used as the specific resin according tothe seventh aspect of the invention.

(Polyamide-Based Resin)

The polyamide-based resin refers to a resin having an amide bond(—NHCO—) in the main chain, and may be thermosetting or thermoplastic.

Examples of the polyamide-based resin include aliphatic polyamides, suchas polycaproamide (nylon-6), poly-ω-aminoheptanoic acid (nylon-7),poly-ω-aminononanoic acid (nylon-9), polyundecaneamide (nylon-11),polylauryl lactam (nylon-12), polyethylene diamine adipamide(nylon-2,6), polytetramethylene adipamide (nylon-4,6), polyhexamethyleneadipamide (nylon-6,6), polyhexamethylene sebacamide (nylon-6,10),polyhexamethylene dodecamide (nylon-6,12), polyoctamethylene adipamide(nylon-8,6) and polydecamethylene adipamide (nylon-10,8); crystallinearomatic polyamides obtained through a polycondensation reaction betweenan aromatic diamine, such as meta-xylene diamine or para-xylene diamine,and a dicarboxylic acid, such as adipic acid, suberic acid, sebacicacid, cyclohexane dicarboxylic acid, terephthalic acid or isophthalicacid, or a derivative thereof, and the like.

Among the above, nylon-6, nylon-6,6, nylon-12 and the like arepreferable, and nylon-12 is more preferable.

Examples of the above polyamide-based resin include UBESTA (for example,3014U, 3020U or the like) manufactured by Ube Industries, Ltd. andVESTAMID (for example, L1600, L1700 or the like) manufactured byDaicel-Evonik Ltd.

(Polyolefin-Based Resin)

The polyolefin-based resin has a principle chain of a polyolefin, suchas ethylene, propylene or 1-butene, and may be thermosetting orthermoplastic.

Examples of the polyolefin-based resin include polyethylene,polypropylene, polybutene, a cyloolefin-based resin, a copolymer ofthese resins, and the like.

Among the above, from the viewpoint of increasing the elastic modulus ofthe thermoplastic resin material, polyethylene and polypropylene arepreferable, and polypropylene and an ethylene-propylene copolymer aremore preferable.

The number average molecular weight of the polyolefin-based resin ispreferably 5,000 to 10,000,000 from the viewpoint of melt moldability.When the number average molecular weight is less than 5,000, there is aconcern that the mechanical properties of a resin composite may degrade.When the number average molecular weight exceeds 10,000,000, there is aconcern that a problem may be caused with the workability of a resincomposite. For the same reasons as above, the number average molecularweight of the polyolefin-based resin is 7,000 to 1,000,000. The numberaverage molecular weight of the polyolefin-based resin is particularlypreferably 10,000 to 1,000,000. Thereby, the mechanical properties andworkability of a resin composite can be further improved.

Examples of the above polyolefin-based resin include commerciallyavailable products of PRIME PP (registered trademark) of Prime PolymerCo., Ltd., NOVATEC PP (registered trademark) and WINTEC (registeredtrademark) of Japan Polypropylene Corporation, and the like.

(Polystyrene-Based Resin)

The polystyrene-based resin refers to a resin including polystyrene, andmay be thermosetting or thermoplastic. The polystyrene-based resin mayinclude one or more polymers which are not the polymer that canconstitute the soft segment of the polystyrene-based thermoplasticelastomer as copolymerization components.

The number average molecular weight of the polystyrene-based resin ispreferably 5,000 to 10,000,000 from the viewpoint of melt moldability.When the number average molecular weight is less than 5,000, there is aconcern that the mechanical properties of a resin composite may degrade.When the number average molecular weight exceeds 10,000,000, there is aconcern that a problem may be caused with the workability of a resincomposite. For the same reasons as above, the number average molecularweight of the polystyrene-based resin is 7,000 to 1,000,000. The numberaverage molecular weight of the polystyrene-based resin is particularlypreferably 10,000 to 1,000,000. Thereby, the mechanical properties andworkability of a resin composite can be further improved.

Examples of the above polystyrene-based resin that can be used includecommercially available products of ZAREK (registered trademark)manufactured by Idemitsu Kosan Co., Ltd., TOYO STYROL (registeredtrademark) manufactured by Toyo-Styrene Co., Ltd., CEVIAN manufacturedby Daicel Polymer Ltd., TECHNO ABS manufactured by Techno Polymer Co.,Ltd., and the like.

[Polyester Resin]

The thermoplastic resin material includes a polyester resin other thanthe thermoplastic elastomer. The polyester-based resin refers to a resinhaving an ester bond in the main chain.

The polyester resin is not particularly limited, but is preferably aresin of the same kind as the polyester resin included in the hardsegment in the polyester-based thermoplastic elastomer, and is morepreferably crystalline polyester.

As the crystalline polyester, an aromatic polyester can be used. Thearomatic polyester can be formed from, for example, an aromaticdicarboxylic acid or an ester-forming derivative and an aliphatic diol.

Examples of the aromatic polyester include polyethylene terephthaliate,polybutylene terephthalate, polystyrene terephthalate, polyethylenenaphthalate, polybutylene naphthalate, and the like, and polybuthyleneterephthalate is preferable.

Examples of the aromatic polyester include polybutylene terephthalatederived from terephthalic acid and/or dimethyl terephthalate and1,4-butanediol, and, furthermore, the aromatic polyester may be apolyester derived from a dicarboxylic acid component, such asisophthalic acid, phthalic acid, naphthalene-2,6-dicarboxylic acid,naphthalene-2,7-dicarboxylic acid, diphenyl-4,4′-dicarboxylic acid,diphenoxyethane dicarboxylic acid, 5-sulfoisophthalic acid, or anester-forming derivative thereof and a diol having a molecular weight of300 or less [for example, an aliphatic diol, such as ethylene glycol,trimethylene glycol, pentamethylene glycol, hexamethylene glycol,neopentyl glycol or decamethylene glycol; an alicyclic diol, such as1,4-cyclohexane dimethanol or tricyclodecane dimethylol; or an aromaticdiol, such as xylene glycol, bis(p-hydroxy)diphenyl,bis(p-hydroxyphenyl)propane, 2,2-bia[4-(2-hydroxyethoxy)phenyl]propane,bis[4-(2-hydroxy)phenyl]sulfone,1,1-bis[4-(2-hydroxyethoxy)phenyl]cyclohexane,4,4′-dihydroxy-p-terphenyl or 4,4′-dihydroxy-p-quarterphenyl], or acopolymerized polyester for which two or more of the dicarboxylic acidcomponent and the diol component are used in combination. In addition, atrifunctional or more polyfunctional carboxylic acid component,polyfunctional oxyacid component, polyfunctional hydroxyl component, orthe like can be copolymerized within a range of 5 mole % or less.

As the above polyester resin, a commercially available product can beused, and examples thereof include “JURANEX” series (for example, 2000,2002, and the like) manufactured by Polyplastic Co., Ltd., NOVADURANseries (for example, 5010R5, 5010R3-2, and the like) manufactured byMitsubishi Engineering Plastics Corporation, “TORECON” series (forexample, 1401X06, 1401X31, and the like) manufactured by TorayIndustries, Inc., and the like.

In addition, the elastic modulus of the polyester resin is preferably700 MPa or more, and more preferably from 800 MPa to 3000 MPa from theviewpoint of increasing the elastic modulus of the thermoplastic resinmaterial. Meanwhile, the elastic modulus of the polyester resin refersto the tensile modulus of elasticity regulated in JIS K7113:1995, andthe elastic modulus of the specific resin according to the seventhaspect of the invention can be measured using, for example, a precisionuniversal tester AUTOGRAPH manufactured by Shimadzu Corporation.

In addition, the elastic modulus of the specific resin according to theseventh aspect of the invention is preferably 100 MPa or more, morepreferably from 100 MPa to 3000 MPa, and still more preferably from 100MPa to 2000 MPa from the viewpoint of increasing the elastic modulus ofthe thermoplastic resin material. Meanwhile, the elastic modulus of thespecific resin according to the seventh aspect of the invention refersto the tensile modulus of elasticity regulated in JIS K7113:1995, andthe elastic modulus of the specific resin according to the seventhaspect of the invention can be measured using, for example, a precisionuniversal tester AUTOGRAPH manufactured by Shimadzu Corporation.

The thermoplastic resin material may include two or more resins.However, at least one of the resins needs to be a resin of the same kindas the hard segment included in the thermoplastic elastomer included inthe thermoplastic resin material (the specific resin according to theseventh aspect of the invention). In addition, two or more kinds of thespecific resin according to the seventh aspect of the invention may alsobe included in the thermoplastic resin material; however, since thethermoplastic resin material preferably includes one thermoplasticelastomer as described above, the thermoplastic resin material alsopreferably includes one kind of the specific resin according to theseventh aspect of the invention.

Since the polyamide-based thermoplastic elastomer is preferably used asthe thermoplastic elastomer included in the thermoplastic resin materialas described above, the specific resin according to the seventh aspectof the invention is preferably a polyamide-based resin, and morepreferably a polyamide-based thermoplastic resin.

In the thermoplastic resin material, the quantitative ratio between thethermoplastic elastomer and the specific resin according to the seventhaspect of the invention (thermoplastic elastomer:the specific resinaccording to the seventh aspect of the invention) is preferably, by massstandard, 95:5 to 50:50, and more preferably 90:10 to 50:50 from theviewpoint of impact resistance.

In addition, the content of the thermoplastic elastomer in thethermoplastic resin material is preferably from 40 mass % to 95 mass %,and more preferably from 50 mass % to 90 mass % with respect to thetotal mass of the thermoplastic resin material from the viewpoint of thesufficient development of the performances of the thermoplasticelastomer.

The thermoplastic resin material may contain a variety of fillers (forexample, silica, calcium carbonate and clay) and a variety of additives,such as an age inhibitor, oil, a plasticizer, a coloring agent, aweather-resisting agent and a reinforcing material, as desired.

The thermoplastic resin material can be obtained by mixing thethermoplastic elastomer and the specific resin according to the seventhaspect of the invention, adding a variety of additives as necessary, andmelting and mixing the components. The mixing ratio between thethermoplastic elastomer and the specific resin according to the seventhaspect of the invention follows the fractions described above. Thethermoplastic resin material obtained through melting and mixing can beused in a pellet shape as necessary.

The tensile modulus of elasticity of the thermoplastic resin materialaccording to the seventh aspect of the invention, which is regulated inJIS K7113:1995, is preferably from 100 MPa to 1000 MPa, more preferablyfrom 100 MPa to 800 MPa, and particularly preferably from 100 MPa to 700MPa. When the tensile modulus of elasticity of the polyamide-basedthermoplastic elastomer is from 100 MPa to 1000 MPa, fitting onto a rimcan be efficiently carried out while holding the shape of the tireframe.

The tensile yield strength of the thermoplastic resin material accordingto the seventh aspect of the invention, which is regulated in JISK7113:1995, is preferably 5 MPa or more, preferably frpm 5 MPa to 20MPa, and still more preferably from 5 MPa to 17 MPa. When the tensileyield strength of the thermoplastic resin material is 5 MPa or more, itis possible to withstand deformation caused by a load applied to thetire while travelling and the like.

The tensile yield elongation of the thermoplastic resin materialaccording to the seventh aspect of the invention, which is regulated inJIS K7113:1995, is preferably 10% or more, preferably from 10% to 70%,and still more preferably from 15% to 60%. When the tensile yieldelongation of the thermoplastic resin material is 10% or more, it ispossible to increase the elastic area and improve fittability onto arim.

The tensile fracture elongation of the thermoplastic resin materialaccording to the seventh aspect of the invention, which is regulated inJIS K7113:1995, is preferably 50% or more, preferably 100% or more,still more preferably 150% or more, and particularly preferably 200% ormore. When the tensile elongation at break of the thermoplastic resinmaterial is 50% or more, it is possible to improve fittability onto arim and make the thermoplastic resin material resistant to fracture dueto collision.

The deflection temperature under load (under a load of 0.45 MPa) of thethermoplastic resin material according to the seventh aspect of theinvention, which is regulated in ISO75-2 or ASTM D648, is preferably 50°C. or more, preferably from 50° C. to 150° C., and still more preferablyfrom 50° C. to 130° C. When the deflection temperature under load of thethermoplastic resin material is 50° C. or more, it is possible tosuppress deflection in a curing step, such as treading.

[Resin Material as a Component of the Reinforcing Cord Layer]

The tire according to the seventh aspect of the invention may have areinforcing cord member that is wound on the outer circumferentialportion of the tire frame in the circumferential direction so as to forma reinforcing cord layer. The “resin material as a component of thereinforcing cord layer” according to the seventh aspect of the inventionis the same as the above “resin material as a component of thereinforcing cord layer” according to the first aspect of the invention.

Embodiment 7-1

Hereinafter, a tier according to Embodiment 7-1 of the tire of theinvention according to the seventh aspect will be described according tothe drawings. Here, the tire according to Embodiment 7-1 is the same asthe above Embodiment 1-1 except for the following facts. Therefore, thesame reference signs and drawings will be used in the descriptionregarding the same drawings and members.

The tire case 17 of the present embodiment is formed of a thermoplasticresin material configured of a mixed material of a polyamide-basedthermoplastic elastomer (“UBESTA, XPA9055X1” manufactured by UbeIndustries, Ltd.) and a polyamide-based thermoplastic resin (“UBESTA,3014U” manufactured by Ube Industries, Ltd.). In the embodiment, thetire case 17 is formed only of the thermoplastic resin materialaccording to the seventh aspect of the invention, but the inventionaccording to the seventh aspect is not limited to this configuration,and, similarly to an ordinary pneumatic rubber tire of the related art,different thermoplastic resin materials having different characteristicsmay be used in the respective portions (side portion 14, crown portion16, bead portion 12, and the like) of the tire case 17. In addition, thetire case 17 may be reinforced using a reinforcing material (amacromolecular material, metal fabric, cord, non-woven fabric, wovenfabric, or the like) by embedding and disposing the reinforcing materialin the tire case 17 (for example, bead portion 12, side portion 14,crown portion 16, and the like).

The tire case 17 of the embodiment is a pair of mutually-bonded tirecase half parts (tire frame pieces) 17A that are formed of thethermoplastic resin material according to the seventh aspect of theinvention. The tire case half part 17A is formed by disposing thecircular tire case half parts 17A, which each have the same shape andhave been formed by integrating a bead portion 12, a side portion 14 anda half-width crown portion 16 through injection molding or the like, soas to face each other, and bonding the tire case half parts 17A at thetire equatorial plane portion. The thermoplastic resin materialaccording to the seventh aspect of the invention includes apolyamide-based thermoplastic elastomer and the specific resin accordingto the seventh aspect of the invention. Other portions are the same asin the tire according to the above Embodiment 1-1, and the manufacturingmethod is also the same.

(Effects)

In the tire 10 of the embodiment, since the tire case 17 is formed ofthe thermoplastic resin material, even when the elastic modulus of thethermoplastic resin material is increased, the tan δ of thethermoplastic resin material is not easily increased, and the rollingresistance of the tire can be suppressed, furthermore, since the tirestructure can be simplified, the weight is light compared to rubber ofthe related art. Therefore, when the tire 10 of the embodiment isapplied to an automobile, since the rolling resistance is suppressed,and the weight of the tire can be decreased, it is possible to improvethe gas mileage of an automobile in which the tire is used.

In addition, when the thermoplastic resin material includes thepolyamide-based thermoplastic elastomer, since the polyamide-basedthermoplastic elastomer has a high adhesion to a reinforcing cord 26,and, furthermore, is excellent in terms of fixing performances, such asweld strength, it is possible to particularly suppress a phenomenon inwhich air remains around the reinforcing cord 26 in a reinforcing cordwinding process (incorporation of air). When the adhesion andweldability to the reinforcing cord 26 are high, and, furthermore, airentrance into the periphery of the reinforcing cord member issuppressed, it is possible to effectively suppress the movement of thereinforcing cord 26 due to a force applied or the like while travelling.Thereby, for example, even when a tire-constituting member has beenprovided so as to cover the entire outer circumferential portion of thetire frame with the reinforcing cord member, since the movement of thereinforcing cord member is suppressed, the separation or the likebetween the members (including the tire frame) is suppressed, and thedurability of the tire 10 is improved.

In addition, in the tire 10 of the embodiment, since the reinforcingcord 26 having a higher stiffness than the thermoplastic resin materialis wound in a spiral shape in the circumferential direction on the outercircumferential surface of the crown portion 16 in the tire case 17formed of the thermoplastic resin material, the puncture resistance, thecutting resistance and the stiffness of the tire 10 in thecircumferential direction are improved. Meanwhile, the improvement ofthe stiffness of the tire 10 in the circumferential direction preventsthe creeping in the tire case 17 formed of the thermoplastic resinmaterial.

In addition, in the cross-sectional view of the tire case 17 in theaxial direction (the cross section illustrated in FIG. 1), since atleast some of the reinforcing cord 26 is embedded in the outercircumferential surface of the crown portion 16 in the tire case 17formed of the thermoplastic resin material, and is adhered to thethermoplastic resin material, incorporation of air during manufacturingis suppressed, and the movement of the reinforcing cord 26 due to aforce applied or the like while travelling is suppressed. Thereby, theseparation or the like of the reinforcing cord 26, the tire case 17 anda tread 30 is suppressed, and the durability of the tire 10 is improved.

In addition, since the depth L of embedding of the reinforcing cord 26is ⅕ or more of the diameter D as illustrated in FIG. 2, incorporationof air during manufacturing is effectively suppressed, and the movementof the reinforcing cord 26 due to a force applied or the like whiletravelling is further suppressed.

When a reinforcing cord layer 28 is configured so as to include thethermoplastic resin material as described above, since it is possible todecrease the difference in hardness between the tire case 17 and thereinforcing cord layer 28 compared to when the reinforcing cord 26 isfixed using cushion rubber, the reinforcing cord 26 can be furtheradhered and fixed to the tire case 17. Thereby, the above incorporationof air can be effectively prevented, and it is possible to effectivelysuppress the movement of the reinforcing cord member during travelling.

Furthermore, when the reinforcing cord is a steel cord, since thereinforcing cord 26 can be easily separated and collected from thethermoplastic resin material through heating when disposing of the tire,it is advantageous in terms of the recycling properties of the tire 10.In addition, the resin material generally has a low loss coefficient(Tan δ) compared to vulcanized rubber. Therefore, when the reinforcingcord layer includes the resin material much, it is possible to improvethe rolling properties of the tire. Furthermore, the resin materialhaving a relatively high elastic modulus compared to vulcanized rubberis advantageous that the in-plane shear stiffness is large, andoperation feeling or abrasion resistance during tire travelling is alsoexcellent.

In addition, since the tread 30 that comes into contact with roadsurfaces is formed using a rubber material that is moreabrasion-resistant than the thermoplastic resin material, the abrasionresistance of the tire 10 is improved.

Furthermore, since a circular bead core 18 made of a metallic materialis embedded in the bead portion 12, similarly to a pneumatic rubber tireof the related art, the tire case 17, that is, the tire 10 is stronglyheld to a rim 20.

In addition, furthermore, since a sealing layer 24 made of a rubbermaterial having higher sealing properties than the thermoplastic resinmaterial is provided in a portion that comes into contact with the rim20 of the bead portion 12, the sealing properties between the tire 10and the rim 20 are improved. Therefore, compared to when the tire issealed with the rim 20 using the thermoplastic resin material, the airleakage in the tire is further suppressed. In addition, the rim fittingproperties are also improved when the sealing layer 24 is provided.

The above embodiment employs a configuration in which the reinforcingcord 26 is heated, and the thermoplastic resin material in the portionwith which the heated reinforcing cord 26 comes into contact is meltedor softened, but the invention according to the seventh aspect is notlimited to this configuration, and the reinforcing cord 26 may beembedded in the crown portion 16 after heating the outer circumferentialsurface of the crown portion 16, in which the reinforcing cord 26 is tobe embedded, using a hot air generating apparatus without heating thereinforcing cord 26.

In addition, in Embodiment 7-1, a heater and a fan are used as the heatsource of a cord heating apparatus 59, but the invention according tothe seventh aspect is not limited to this configuration, and aconfiguration in which the reinforcing cord 26 is directly heated usingradiation heat (for example, infrared rays or the like) may be employed.

Furthermore, Embodiment 7-1 employs a configuration in which theportion, in which the thermoplastic resin material having thereinforcing cord 26 embedded therein is melted or softened, is forciblycooled using a second metal roller 64, but the invention according tothe seventh aspect is not limited to this configuration, and aconfiguration in which the portion, in which the thermoplastic resinmaterial is melted or softened, is forcibly cooled and solidified bydirectly blowing cold air to the portion in which the thermoplasticresin material is melted or softened.

In addition, Embodiment 7-1 employs a configuration in which thereinforcing cord 26 is heated; however, for example, a configuration inwhich the outer circumference of the reinforcing cord 26 is coated withthe same thermoplastic resin material as the tire case 17 may beemployed, and, in this case, it is possible to effectively suppress airentrance during embedding in the crown portion 16 by heating thethermoplastic resin material, which is coated with the reinforcing cord26, when winding the coated reinforcing cord around the crown portion 16of the tire case 17.

In addition, the spiral winding of the reinforcing cord 26 facilitatesthe manufacturing, but a method, in which the reinforcing cord 26 isdiscontinuously formed in the width direction, or the like can be alsoconsidered.

The tire 10 of Embodiment 7-1 is a so-called tubeless tire in which anair chamber is formed between the tire 10 and the rim 20 by mounting thebead portion 12 in the rim 20, but the invention according to theseventh aspect is not limited to this configuration, and the tire mayhave a complete tube shape.

The tire having the complete tube shape may be an aspect in which, forexample, three circular-shaped tire frames are disposed in the tirewidth direction as illustrated in FIG. 4. FIG. 4 is a cross-sectionalview of the tire according to other embodiment. As illustrated in FIG.4, a tire 86 has a tread rubber layer 87, circular-shaped hollow tubes(tire frame) 88 which are formed of the same resin material as inEmbodiment 7-1, a belt (reinforcing cord) 89 and a rim 90. Three tubes88 are disposed in series in the tire width direction of the tire 86.The tread rubber layer 87, in which the belt 89 is embedded, is adheredto the outer circumferential portions of the tubes 88. In addition, thetubes 88 are mounted on the rim 90 having recess portions that engagewith the tubes 88. Meanwhile, the bead core is not provided in the tire86.

Thus far, an embodiment of the invention according to the seventh aspecthas been described using the embodiment, but the embodiment is simply anexample, and the invention can be carried out with a variety ofmodifications within the scope of the purport. In addition, it isneedless to say that the scope of right of the invention according tothe seventh aspect is not limited to the above embodiment.

Embodiment 7-2

Next, a method of manufacturing the tire according to the seventh aspectof the invention and Embodiment 7-2 of the tire will be describedaccording to the drawings. Similarly to the above Embodiment 7-1, thetire of the present embodiment exhibits almost the same cross-sectionalshape as an ordinary pneumatic rubber tire of the related art.

Here, the tire according to Embodiment 7-2 is the same as the aboveEmbodiment 1-2 except for the following facts. Therefore, the samereference signs and drawings will be used in the description regardingthe same drawings and members.

In the tire of Embodiment 7-2, similarly to the above Embodiment 7-1,the tire case 17 is formed of a mixed material of a polyamide-basedthermoplastic elastomer (“UBESTA, XPA9055X1” manufactured by UbeIndustries, Ltd.) and a polyamide-based thermoplastic resin (“UBESTA,3014U” manufactured by Ube Industries, Ltd.). In the tire 200 of theembodiment, the reinforcing cord layer 28 that is formed by winding acoated cord member 26B in the circumferential direction (illustrated inFIG. 6 using a broken line) is superposed on the crown portion 16 asillustrated in FIGS. 5 and 6. The reinforcing cord layer 28 configuresthe outer circumferential portion of the tire case 17, and reinforcesthe stiffness of the crown portion 16 in the circumferential direction.Meanwhile, the outer circumferential surface of the reinforced cordlayer 28 is included in the outer circumferential surface 17S of thetire case 17.

In addition, the elastic modulus of a resin material for coating 27 ispreferably set in a range of 0.1 times to 10 times the elastic modulusof a resin material that forms the tire case 17. When the elasticmodulus of the resin material for coating 27 is 10 times or less theelastic modulus of the thermoplastic resin material that forms the tirecase 17, the crown portion does not become too hard, and fittabilityonto a rim are easily achieved. In addition, when the elastic modulus ofthe resin material for coating 27 is 0.1 times or more the elasticmodulus of the thermoplastic resin material that forms the tire case 17,the resin that configures the reinforcing cord layer 28 does not becometoo soft, and the belt in-plane shear stiffness is excellent whereby thecornering force is improved. Meanwhile, in the embodiment, as the resinmaterial for coating 27, the same material as the thermoplastic resinmaterial (in the embodiment, a mixed material of a polyamide-basedthermoplastic elastomer (“UBESTA, XPA9055X1” manufactured by UbeIndustries, Ltd.) and a polyamide-based thermoplastic resin (“UBESTA,3014U” manufactured by Ube Industries, Ltd.).) is used. Other portionsare the same as in the tire according to the above Embodiment 1-2, andthe manufacturing method is also the same.

(Effects)

In the tire 200 of the embodiment, since the tire case 17 is formed ofthe thermoplastic resin material, even when the elastic modulus of thethermoplastic resin material is increased, the tan δ of thethermoplastic resin material does not easily increase, and the rollingresistance of the tire can be suppressed. Furthermore, since the tirestructure can be simplified, the weight is light compared to rubber ofthe related art. Therefore, since the weight of the tire 200 of theembodiment can be decreased, it is possible to improve the gas mileageof an automobile in which the tire is used.

In addition, when the reinforcing cord layer 28 is configured to includethe coated cord member 26B, since it is possible to decrease thedifference in hardness between the tire case 17 and the reinforcing cordlayer 28 compared to when the reinforcing cord 26A is simply fixed usingcushion rubber 29, the coated cord member 26B can be further adhered andfixed to the tire case 17. Thereby, the above incorporation of air canbe effectively prevented, and it is possible to effectively suppress themovement of the reinforcing cord member while travelling.

Furthermore, when the reinforcing cord is a steel cord, since the cordmember 26A can be easily separated and collected from the coated cordmember 26B through heating at the time of disposition of the tire, it isadvantageous in terms of the recycling properties of the tire 200. Inaddition, the resin material generally has a low loss coefficient (Tanδ) compared to vulcanized rubber. Therefore, when the reinforcing cordlayer includes the resin material much, it is possible to improve therolling properties of the tire. Furthermore, the resin material having arelatively high elastic modulus compared to vulcanized rubber has theadvantage that the in-plane shear stiffness is large, and operationfeeling or abrasion resistance during tire travelling is also excellent.

In the method of manufacturing the tire of the embodiment, when the tirecase 17, the cushion rubber 29 and a tread rubber 30A are integrated,since the outer circumferential surface 17S of the tire case 17 has beentreated to be coarse, the bonding properties (adhesion) is improved dueto the anchor effect. In addition, since the resin material that formsthe tire case 17 is dug out by the collision of a blasting abrasive, thewettability of an adhesive is improved. Thereby, a state in which theadhesive is uniformly coated on the outer circumferential surface 17S ofthe tire case 17 is held, and the bonding strength between the tire case17 and the cushion rubber 29 can be ensured.

Particularly, even when protrusions and recesses are formed on the outercircumferential surface 17S of the tire case 17, the peripheries of therecess portions (recess walls and recess bottoms) are treated to becoarse by making the blasting abrasive collide with the recess portions(voids 28A), and the bonding strength between the tire case 17 and thecushion rubber 29 can be ensured.

Meanwhile, since the cushion rubber 29 is laminated in thecoarsening-treated areas on the outer circumferential surface 17S of thetire case 17, the bonding strength between the tire case 17 and thecushion rubber can be effectively ensured.

When the cushion rubber 29 has been vulcanized in a vulcanizing process,the cushion rubber 29 flows into the coarsened recesses and protrusionsformed on the outer circumferential surface 17S of the tire case 17through the coarsening treatment. In addition, when vulcanization iscompleted, the anchor effect is developed due to the cushion rubber 29that has flowed into the coarsened recesses and protrusions so that thebonding strength between the tire case 17 and the cushion rubber 29 isimproved.

In the tire 200 manufactured using the above method of manufacturing atire, the bonding strength between the tire case 17 and the cushionrubber 29 is ensured, that is, the bonding strength between the tirecase 17 and the tread 30 is ensured through the cushion rubber 29.Thereby, the separation between the outer circumferential surface 17S ofthe tire case 17 of the tire 200 and the cushion rubber 29 is suppressedwhile travelling and the like.

In addition, since the outer circumferential portion of the tire case 17is configured of the reinforcing cord layer 28, the puncture resistanceand the cutting resistance are improved, compared to a tire case havingthe outer circumferential portion configured of something other than thereinforcing cord layer 28.

In addition, since the reinforcing cord layer 28 is formed by windingthe coated cord member 26B, the stiffness of the tire 200 in thecircumferential direction is improved. The improvement of the stiffnessin the circumferential direction suppresses creeping (a phenomenon inwhich the plastic deformation of the tire case 17 increases over timeunder a constant stress) in the tire case 17, and the pressureresistance with respect to the air pressure from the inside in the tirediameter direction is improved.

In the embodiment, the recesses and protrusions are configured on theouter circumferential surface 17S of the tire case 17, but the seventhaspect of the invention is not limited thereto, and a configuration inwhich the outer circumferential surface 17S is formed to be flat may beemployed.

In addition, in the tire case 17, the reinforcing cord layer may beformed such that the coated cord member, which is wound around andbonded to the crown portion of the tire case, is covered with athermoplastic material for coating. In this case, a coated layer can beformed by discharging a thermoplastic material for coating in a moltenor softened state on the reinforcing cord layer 28. In addition, thecoated layer may be formed by heating an adhesive sheet into a molten orsoftened state without using an extruder, and attaching the adhesivesheet to the surface (outer circumferential surface) of the reinforcingcord layer 28.

The above Embodiment 7-2 employs a configuration in which partitionedcase bodies (tire case half parts 17A) are bonded so as to form the tirecase 17, but the seventh aspect of the invention is not limited thereto,and the tire case 17 may be integrally formed using a mold or the like.

The tire 200 of Embodiment 7-2 is a so-called tubeless tire in which anair chamber is formed between the tire 200 and the rim 20 by mountingthe bead portion 12 in the rim 20, but the seventh aspect of theinvention is not limited to this configuration, and the tire 200 mayhave, for example, a complete tube shape (for example, the shapeillustrated in FIG. 4).

In Embodiment 7-2, the cushion rubber 29 is disposed between the tirecase 17 and the tread 30, but the seventh aspect of the invention is notlimited thereto, and a configuration in which the cushion rubber 29 isnot disposed may be employed.

In addition, Embodiment 7-2 employs a configuration in which the coatedcord member 26B is wound around the crown portion 16 in a spiral shape,but the seventh aspect of the invention is not limited thereto, and aconfiguration in which the coated cord member 26B is wound around to bediscontinuous in the width direction may be employed.

Embodiment 7-2 employs a configuration in which a thermoplastic materialis used as the resin material for coating 27 that forms the coated cordmember 26B, and the resin material for coating 27 is heated into amolten or softened state so as to weld the coated cord member 26B on theouter circumferential surface of the crown portion 16, but the seventhaspect of the invention is not limited to this configuration, and aconfiguration in which the coated cord member 26B is welded on the outercircumferential surface of the crown portion 16 using an adhesive or thelike without heating the resin material for coating 27 may be employed.

In addition, a configuration in which a thermosetting resin is used asthe resin material for coating 27 that forms a coated cord member 26Band the coated cord member 26B is welded on the outer circumferentialsurface of the crown portion 16 using an adhesive or the like withoutheating may be employed.

Furthermore, a configuration in which a thermosetting resin is used asthe resin material for coating 27 that forms the coated cord member 26Band the tire case 17 is formed of a thermoplastic resin material may beemployed. In this case, the coated cord member 26B may be adhered to theouter circumferential surface of the crown portion 16 using an adhesiveor the like, or the coated cord member 26B may be welded on the outercircumferential surface of the crown portion 16 by heating the portionprovided with the coated cord member 26B of the tire case 17 into amolten or softened state.

In addition, furthermore, a configuration in which a thermoplasticmaterial is used as the resin material for coating 27 that forms thecoated cord rubber 26B, and the tire case 17 is formed of athermoplastic resin material. In this case, the coated cord member 26Bmay be adhered to the outer circumferential surface of the crown portion16 using an adhesive or the like, or the coated cord member 26B may bewelded on the outer circumferential surface of the crown portion 16 byheating into a molten or softened state the portion of the tire case 17at which the coated cord member 26B is provided, and heating the resinmaterial for coating 27 into a molten or softened state. Meanwhile, whenboth the tire case 17 and the coated cord member 26B have been heatedinto a molten or softened state, since both are well mixed, the bondingstrength is improved. In addition, when thermoplastic resin materialsare used as both the resin material that forms the tire case 17 and theresin material for coating 27 that forms the coated cord member 26B, thethermoplastic resin materials are preferably the same kind ofthermoplastic materials, particularly, the same thermoplastic material.

In addition, furthermore, an adhesive may be coated on the outercircumferential surface 17S of the tire case 17, on which the coarseningtreatment has been carried out, after the surface of the outercircumferential surface 17S is activated using a corona treatment, aplasma treatment or the like, thereby increasing hydrophilicity.

In addition, furthermore, the order for manufacturing the tire 200 isnot limited to the order in Embodiment 7-2, and may be appropriatelychanged.

Thus far, an embodiment according to the seventh aspect of the inventionhas been described using the embodiment, but the embodiment is simply anexample, and the invention can be carried out with a variety ofmodifications within the scope of the purport. In addition, it isneedless to say that the scope of right of the invention according tothe seventh aspect is not limited to the above embodiment.

Thus far, the specific embodiments of the invention according to theseventh aspect of the invention have been described using Embodiment 7-1and Embodiment 7-2, but the seventh aspect of the invention is notlimited to the above embodiments.

<<Eighth Aspect of the Invention>>

Next, a resin material as a component of the tire frame according to aneighth aspect of the invention will be described, and, subsequently, aspecific embodiment of the tire according to the eighth aspect of theinvention will be described using the drawings.

[Resin Material]

The tire according to the eighth aspect of the invention is a tireincluding at least a circular tire frame formed of a resin material, andthe resin material includes at least a thermoplastic elastomer and aresin which is other than the thermoplastic elastomer, has a glasstransition temperature of 20° C. or lower, and has an elastic moduluslarger than the elastic modulus of the thermoplastic elastomer.

An elastic modulus can be obtained in a preferable range, and increaseof the rolling resistance of the tire can be suppressed by applying acombination of a thermoplastic elastomer and a resin having a glasstransition temperature in the above range, which is other than thethermoplastic elastomer, (the specific resin according to the eighthaspect of the invention) as the resin material that is a component ofthe circular tire frame that forms the tire.

Hereinafter, the thermoplastic elastomer and the specific resinaccording to the eighth aspect of the invention will be described.

[Thermoplastic Elastomer]

The “thermoplastic elastomer” refers to a resin material including ahard segment and a soft segment in a molecule thereof as describedabove, and, in detail, to a resin material which is an elasticmacromolecular compound and is formed of a copolymer having a polymerconstituting a hard segment that is crystalline and has a high meltingpoint or a hard segment forming a pseudo-crosslink through physicalagglomeration and a polymer constituting a soft segment that isnon-crystalline and has a low glass transition temperature. Meanwhile,the thermoplastic elastomer does not encompass vulcanized rubber, suchas natural rubber or synthetic rubber of the related art.

Examples of the thermoplastic elastomer include polyamide-basedthermoplastic elastomers, polyester-based thermoplastic elastomer,polyolefin-based thermoplastic elastomers, polyurethane-basedthermoplastic elastomers, polystyrene-based thermoplastic elastomers andthe like.

(Polyamide-Based Thermoplastic Elastomer)

The “polyamide-based thermoplastic elastomer” is an elasticmacromolecular compound, and refers to a resin material which is formedof a copolymer having a polymer constituting a hard segment that iscrystalline and has a high melting point, and a polymer constituting asoft segment that is non-crystalline and has a low glass transitiontemperature, and has an amid bond (—CONH—) in the main chain of thepolymer constituting the hard segment.

Examples of crystalline polyamide constituting the hard segment includealiphatic amides, such as polycaproamide (nylon-6),poly-ω-aminoheptanoic acid (nylon-7), poly-ω-aminononanoic acid(nylon-9), polyundecaneamide (nylon-11), polylauryl lactam (nylon-12),polyethylene diamine adipamide (nylon-2,6), polytetramethylene adipamide(nylon-4,6), polyhexamethylene adipamide (nylon-6,6), polyhexamethylenesebacamide (nylon-6,10), polyhexamethylene dodecamide (nylon-6,12),polyoctamethylene adipamide (nylon-8,6) and polydecamethylene adipamide(nylon-10,8); crystalline aromatic polyamides obtained through apolycondensation reaction between an aromatic diamine, such asmeta-xylene diamine or para-xylene diamine, and a dicarboxylic acid,such as adipic acid, suberic acid, sebacic acid, cyclohexanedicarboxylic acid, terephthalic acid or isophthalic acid, or aderivative thereof; and the like.

As the “polyamide-based thermoplastic elastomer” in the presentembodiment, the same polyamide-based thermoplastic elastomer as theabove first aspect of the invention can be used.

(Polyolefin-Based Thermoplastic Elastomer)

Examples of the “polyolefin-based thermoplastic elastomer” include amaterial in which at least a polyolefin constitutes the hard segmentthat is crystalline and has a high melting point, and another polymer(for example, the above polyolefin or other polyolefin) constitutes thesoft segment that is non-crystalline and has a low glass transitiontemperature. Examples of the polyolefin that forms the hard segmentinclude polyethylene, polypropylene, isotactic polypropylene,polybutene, and the like. The “polyolefin-based thermoplastic elastomer”in the embodiment is the same as in the above second aspect of theinvention.

(Polyurethane-Based Thermoplastic Elastomer)

The “polyurethane-based thermoplastic elastomer” is an elasticmacromolecular compound, and refers to a resin material which is formedof a copolymer having a polymer constituting the hard segment forming apseudo-crosslink through physical agglomeration and a polymerconstituting the soft segment that is non-crystalline and has a lowglass transition temperature, and has a urethane bond in the main chainof the polymer constituting the hard segment. The “polyurethane-basedthermoplastic elastomer” in the embodiment is the same as in the abovesecond aspect of the invention.

(Polystyrene-Based Thermoplastic Elastomer)

Examples of the “polystyrene-based thermoplastic elastomer” include amaterial in which at least polystyrene constitutes the hard segment, andanother polymer (for example, polybutadiene, polyisoprene, polyethylene,hydrogenated polybutadiene, hydrogenated polyisoprene, or the like)constitutes the soft segment that is non-crystalline and has a low glasstransition temperature. Among the above, nylon-6, nylon-6,6, nylon-12,and the like are preferable, and nylon-12 is more preferable. The“polyolefin-based thermoplastic elastomer” in the embodiment is the sameas in the above second aspect of the invention.

(Polyester-Based Thermoplastic Elastomer)

Examples of the polyester-based thermoplastic elastomer include amaterial in which at least a polyester constitutes the hard segment thatis crystalline and has a high melting point, and another polymer (forexample, polyester, polyether, or the like) constitutes the soft segmentthat is non-crystalline and has a low glass transition temperature. The“polyester-based thermoplastic elastomer” in the embodiment is the sameas in the above second aspect of the invention.

The resin material may include two or more thermoplastic elastomers, butthe resin material preferably includes one thermoplastic elastomer fromthe viewpoint of controlling the tire performances of a tire formedusing the resin material.

Among the thermoplastic elastomers described above, at least oneselected from the polyamide-based thermoplastic elastomers, thepolyester-based thermoplastic elastomer, the polystyrene-basedthermoplastic elastomers and the polyurethane-based thermoplasticelastomers is preferably used, and, furthermore, the polyamide-basedthermoplastic elastomer or the polyester-based thermoplastic elastomeris preferable since the polyamide-based thermoplastic elastomer or thepolyester-based thermoplastic elastomer has thermal resistance and isexcellent in term of tensile modulus of elasticity, tensile strength andfracture strain, the structure of the tire can be simplified compared toa rubber tire of the related art, and, consequently, reduction in weightof the tire can be realized.

Further, the glass transition temperature (Tg) of the thermoplasticelastomer is preferably from 30° C. to 50° C., and more preferably from25° C. to 70° C. in order to decrease the influence on the rollingresistance, that is, in order to suppress the tan δ at 30° C. to 50° C.The glass transition temperature can be measured using the same methodas for the glass transition temperature in a specific resin according tothe eighth aspect of the invention described below.

In addition, the elastic modulus of the thermoplastic elastomer is lowerthan the elastic modulus of the specific resin according to the eighthaspect of the invention since the elastic modulus of the thermoplasticelastomer is increased by adding the specific resin according to theeighth aspect of the invention, is preferably from 5 MPa to 700 MPa, andmore preferably from 10 MPa to 500 MPa. The elastic modulus refers tothe tensile modulus of elasticity regulated in JIS K7113:1995, and canbe measured using, for example, a precision universal tester AUTOGRAPHmanufactured by Shimadzu Corporation.

In addition, the tan δ of the thermoplastic elastomer according to theeighth aspect of the invention is preferably from 0 to 0.1, and morepreferably from 0 to 0.07 in order to suppress the tan δ at 30° C. to50° C. The tan δ can be measured using, for example, ARESIIImanufactured by Rheometric Scientific, Inc. under the conditions of 30°C., 20 Hz and 1% of shear distortion.

[The Specific Resin According to the Eighth Aspect of the Invention]

The resin material includes a resin having a glass transitiontemperature of 20° C. or lower and an elastic modulus larger than theelastic modulus of the thermoplastic elastomer, which is other than thethermoplastic elastomer, (the specific resin according to the eighthaspect of the invention).

Further, the resin according to the eighth aspect of the inventionrefers to a thermoplastic or thermosetting resin, and does not encompassvulcanized rubber, such as natural rubber or synthetic rubber of therelated art.

The glass transition temperature (Tg) is more preferably 15° C. orlower, and particularly preferably 10° C. or lower. Further, the lowerlimit value is not particularly limited, but the glass transitiontemperature is preferably equal to or greater than −200° C., andparticularly preferably equal to or greater than −150° C.

When the specific resin according to the eighth aspect of the inventionhaving a glass transition temperature of the upper limit value or lessis added to the thermoplastic elastomer, and used, the resin materialhas a desired elastic modulus, and the tan δ can be suppressed at a lowlevel. As a result, in the invention according to the eighth aspect, apreferable elastic modulus can be obtained, and the rolling resistanceof the tire can be reduced.

Here, the glass transition temperature of the specific resin accordingto the eighth aspect of the invention can be measured from thetemperature dependency of the dynamic loss (tan δ). For example, theglass transition temperature can be measured using, for example, ARESIIImanufactured by Rheometric Scientific, Inc. under the conditions of 10Hz and 0.2% of shear distortion. Alternatively, the glass transitiontemperature can be measured using a differential scanning calorimetry(DSC).

As the specific resin according to the eighth aspect of the invention,for example, among the resins listed as examples of the resin which isnot modified by an acid (other resin) described below, resins satisfyingthe glass transition temperature (Tg) and the relationship of theelastic modulus with the thermoplastic elastomer or acid-modified resinsdescribed below can be used.

Further, the specific resin according to the eighth aspect of theinvention is more preferably an acid-modified resin. The “acid-modifiedresin” refers to a resin obtained by bonding an unsaturated compoundhaving an acidic group, such as a carboxylic acid group, a sulfuric acidgroup or a phosphoric acid group, to a resin. For example, when anunsaturated carboxylic acid (generally, maleic acid anhydride) is usedas the unsaturated compound having an acidic group, the unsaturated bondportion of the unsaturated carboxylic acid is bonded (for example, graftpolymerization) to an olefin-based resin.

When the acid-modified resin is used, the resin material has asea-island structure having a sea phase constituted of a thermoplasticelastomer and an island phase constituted of the acid-modified resin.When the interaction at the phase interface between the sea phase andthe island phase is weak, the fluidity of the resin material isincreased, which results in excellent injection moldability. Since theacid-modified resin has an acid-modified portion in the molecule, theinteraction with the thermoplastic elastomer is strong, compared to aresin which is not modified by an acid.

The acid-modified resin is preferably a compound having a carboxylicacid group, which is a weak acid group, from the viewpoint ofsuppressing the deterioration of the thermoplastic elastomer, andexamples thereof include acrylic acid, methacrylic acid, itaconic acid,crotonic acid, isocrotonic acid, maleic acid, and the like.

Examples of the acid-modified resin include an acid-modified polyolefinresin and the like. Among the above, acid-modified polyethylene,acid-modified polypropylene, acid-modified ethylene-propylenecopolymers, ethylene-vinyl acetate copolymers are preferable.

Examples of the acid-modified polyolefin include ADOMER QF551, QE060,LB548, NE827, QB550 and the like manufactured by Mitsui Chemicals, Inc.

The acid value of the acid-modified resin needs to exceed 0 mg(CH₃ONa)/g. The acid value is measured as the mass [mg] of sodiummethoxide (CH₃ONa) used when neutralization titration is carried out onthe respective acid-modified resin 1 [g] using sodium methoxide(CH₃ONa).

In the sea-island structure, there is a tendency for the island phase tobecome smaller as the acid value increases, and there is a tendency forthe island phase to become larger as the acid value decreases. Byincluding the acid-modified resin, the island phase is finely dispersedin the thermoplastic elastomer.

Meanwhile, the island phase of the acid-modified resin finely dispersedin the resin material can be confirmed through photograph observationusing SEM (a scanning electron microscope).

Further, the elastic modulus of the specific resin according to theeighth aspect of the invention is higher than the elastic modulus of thethermoplastic elastomer in order to increase the elastic modulus. Theelastic modulus is preferably from 100 MPa to 3000 MPa, and morepreferably from 300 MPa to 2000 MPa. The elastic modulus refers to thetensile modulus of elasticity regulated in JIS K7113:1995, and can bemeasured using the method described in the above thermoplasticelastomer.

In addition, the tan δ of the specific resin according to the eighthaspect of the invention preferably has a peak of the tan δ at −150° C.to 20° C., and more preferably has a peak at −150° C. to 15° C. in orderto decrease the tan δ of the resin material. The tan δ can be measuredusing the method described in the above thermoplastic elastomer.

Further, the resin material may include two or more kinds of thespecific resin according to the eighth aspect of the invention.

[Resin which is not Modified by Acid (Other Resin)]

When the resin material includes the acid-modified resin as the specificresin according to the eighth aspect of the invention, the resinmaterial may further include a resin which is not modified by an acid(other resin) and which is other than the thermoplastic elastomer.

In addition, when the resin material does not include the acid-modifiedresin as the specific resin according to the eighth aspect of theinvention, the resin material may include a resin which is not modifiedby an acid (other resin, which satisfies the conditions of the specificresin according to the eighth aspect of the invention) as the specificresin according to the eighth aspect of the invention. Further, when thethermoplastic elastomer is a polystyrene-based thermoplastic elastomer,since the polystyrene-based thermoplastic elastomer does not include apolar group, a resin which is not modified by an acid is preferably usedas the specific resin according to the eighth aspect of the invention.

The resin which is not modified by an acid refers to a resin having anacid value of 0 mg/g.

Further, the resin in the invention according to the eighth aspectrefers to a thermoplastic or thermosetting resin, and does not includevulcanized rubber, such as natural rubber or synthetic rubber of therelated art.

As such, when the resin material contains the thermoplastic elastomer,the acid-modified specific resin according to the eighth aspect of theinvention, and, furthermore, the resin which is not modified by an acid(other resin), the tensile characteristics as the tire performances,such as tensile elasticity and breaking strength, can be improved.

Examples of the other resin include polyolefin resins and the like.Among the above, polypropylene, polyethylene, ethylene-propylenecopolymers, and the like can be exemplified, and polypropylene andethylene-propylene copolymers are preferable particularly from theviewpoint of improving the tensile characteristics, such as tensileelasticity and breaking strength.

Examples of the polypropylene and the ethylene-propylene copolymersinclude J-700GP (homopolymer), JP-2000GP (homopolymer), J-466HP (blockpolymer), J-106MG (homopolymer), J-226T (random polymer) manufactured byPrime Polymer Co., Ltd., NOVATEC EC9EV (block polymer), Wintec WFW4(random polymer) manufactured by Japan Polypropylene Corporation, andthe like.

In addition, the tan δ of other resin preferably has a peak of the tan δat −150° C. to 20° C., and more preferably has a peak at −150° C. to 15°C. in order to decrease the tan δ of the resin material. The tan δ canbe measured in accordance with the method described in the abovethermoplastic elastomer.

Further, when the resin material contains the thermoplastic elastomer,the acid-modified specific resin according to the eighth aspect of theinvention, and, furthermore, the resin which is not modified by an acid(other resin), the tan δ of the other resin is not particularly limitedto the above range.

In addition, the elastic modulus of the specific resin according to theeighth aspect of the invention is higher than the elastic modulus of thethermoplastic elastomer in order to increase the elastic modulus, ispreferably from 100 MPa to 3000 MPa, and more preferably from 300 MPa to2000 MPa. The elastic modulus refers to the tensile modulus ofelasticity regulated in JIS K7113:1995, and can be measured inaccordance with the method described in the above thermoplasticelastomer.

Further, the resin material may include two or more kinds of the otherresin.

[Combination and Ratio]

In the resin material of the invention according to the eighth aspect,the ratio of the total amount of the specific resin according to theeighth aspect of the invention and other resin to the thermoplasticelastomer (the thermoplastic elastomer:the specific resin according tothe eighth aspect of the invention+the other resin [mass ratio]) ispreferably from 95:5 to 55:45, and more preferably from 95:5 to 60:40from the viewpoint of making the thermoplastic elastomer form the seaphase in the sea-island structure.

In addition, when both the specific resin according to the eighth aspectof the invention and the other resin are included, the ratio of theother resin to the specific resin according to the eighth aspect of theinvention (the specific resin according to the eighth aspect of theinvention:the other resin [mass ratio]) is preferably from 100:0 to5:95, and more preferably from 100:0 to 10:90 from the viewpoint ofproviding the interaction with the thermoplastic elastomer.

Furthermore, the total content of the thermoplastic elastomer, thespecific resin according to the eighth aspect of the invention, and theother resin in the resin material is preferably from 50 mass % to 100mass % with respect to the total mass of the resin material from theviewpoint of sufficiently developing performances of the thermoplasticelastomer.

The combination of the thermoplastic elastomer, the specific resinaccording to the eighth aspect of the invention, and the other resin inthe resin material of the invention according to the eighth aspect ispreferably the following combination.

-   -   A combination of the polyamide-based thermoplastic elastomer and        the acid-modified polyolefin resin    -   A combination of the polyamide-based thermoplastic elastomer,        the acid-modified polyolefin resin and polypropylene    -   A combination of the polyamide-based thermoplastic elastomer,        the acid-modified polyolefin resin and an ethylene-propylene        copolymer    -   A combination of the polyester-based thermoplastic elastomer and        the acid-modified polyolefin resin    -   A combination of the polyester-based thermoplastic elastomer,        the acid-modified polyolefin resin and polypropylene    -   A combination of the polyester-based thermoplastic elastomer,        the acid-modified polyolefin resin and an ethylene-propylene        copolymer    -   A combination of the polystyrene-based thermoplastic elastomer        and the polyolefin resin

[Other Compositions and the Properties of the Resin Material]

The resin material may contain a variety of fillers (for example,silica, calcium carbonate and clay) and a variety of additives, such asan age inhibitor, oil, a plasticizer, a coloring agent, aweather-resisting agent and a reinforcing material, as desired.

The resin material can be obtained by mixing the thermoplastic elastomerand the specific resin according to the eighth aspect of the invention,adding other resin or a variety of additives as necessary, and meltingand mixing the components. The mixing ratio of the thermoplasticelastomer and the specific resin according to the eighth aspect of theinvention follows the fractions described above. The resin materialobtained through melting and mixing can be used in a pellet shape asnecessary.

The tensile modulus of elasticity of the resin material according to theeighth aspect of the invention, which is regulated in JIS K7113:1995, ispreferably from 100 MPa to 1000 MPa, more preferably from 100 MPa to 800MPa, and particularly preferably from 100 MPa to 700 MPa. When thetensile modulus of elasticity of the resin material is from 100 MPa to1000 MPa, fitting onto a rim can be efficiently carried out whileholding the shape of the tire frame.

The tensile yield strength of the resin material according to the eighthaspect of the invention, which is regulated in JIS K7113:1995, ispreferably 5 MPa or more, preferably from 5 MPa to 20 MPa, and stillmore preferably from 5 MPa to 17 MPa. When the tensile yield strength ofthe resin material is 5 MPa or more, it is possible to withstanddeformation caused by a load applied to the tire while travelling andthe like.

The tensile yield elongation of the resin material according to theeighth aspect of the invention, which is regulated in JIS K7113:1995, ispreferably 10% or more, preferably from 10% to 70%, and still morepreferably from 15% to 60%. When the tensile yield elongation of theresin material is 10% or more, it is possible to increase the elasticarea and improve rim assembling properties.

The tensile fracture elongation of the resin material according to theeighth aspect of the invention, which is regulated in JIS K7113:1995, ispreferably 50% or more, preferably 100% or more, still more preferably150% or more, and particularly preferably 200% or more. When the tensilefracture elongation of the resin material is 50% or more, it is possibleto improve the rim assembling properties and make the resin materialhave resistance to fracture caused by collision.

The deflection temperature under load (under a load of 0.45 MPa) of theresin material according to the eighth aspect of the invention, which isregulated in ISO75-2 or ASTM D648, is preferably equal to or greaterthan 50° C., preferably from 50° C. to 150° C., and still morepreferably from 50° C. to 130° C. When the deflection temperature underload of the resin material is equal to or greater than 50° C., it ispossible to suppress deformationt of tread or the like in thevulcanization step.

[Resin Material as a Component of the Reinforcing Cord Layer]

The tire according to the eighth aspect of the invention may have thereinforcing cord member which is wound around the outer circumferentialsurface of the tire frame in the circumferential direction so as to formthe reinforcing cord layer.

The “resin material as a component of the reinforcing cord layer”according to the eighth aspect are the same as the “resin material as acomponent of the reinforcing cord layer” according to the first aspectof the invention.

Embodiment 8-1

Hereinafter, a tier according to Embodiment 8-1 of the tire according tothe eighth aspect of the invention will be described according to thedrawings.

Here, the tire according to Embodiment 8-1 is the same as the aboveEmbodiment 1-1 except for the following facts. Therefore, the samereference signs and drawings will be used in the description regardingthe same drawings and members.

The tire case 17 of the embodiment is formed of a resin materialcontaining a polyamide-based thermoplastic elastomer (UBESTA, XPA9048manufactured by Ube Industries, Ltd.) and an acid-modified polyolefin(ADOMER QE060 manufactured by Mitsui Chemicals, Inc., a glass transitiontemperature 4° C.) (hereinafter referred to simply as “resin material”in the description of Embodiment 8-1). In the present embodiment, thetire case 17 is formed of a single resin material, the inventionaccording to the eighth aspect is not limited to this configuration,and, similarly to an ordinary pneumatic rubber tire of the related art,different thermoplastic resin materials having different characteristicsmay be used in the respective portions (side portion 14, crown portion16, bead portion 12, and the like) of the tire case 17. Other portionsare the same as in the tire according to the above Embodiment 1-1, andthe manufacturing method is the same as well.

(Effects)

In the tire 10 of the embodiment, since the tire case 17 is formed ofthe resin material further including the specific resin according to theeighth aspect of the invention having a glass transition temperature inthe above range in addition to the thermoplastic elastomer, a favorableelastic modulus can be obtained in the tire case 17, and an increase inthe rolling resistance of the tire can be suppressed.

In addition, the resin material has a high adhesion to the reinforcingcord 26, and, furthermore, is excellent in terms of fixing performances,such as weld strength. Therefore, it is possible to suppress thephenomenon in which air remains around the reinforcing cord 26 in thereinforcing cord winding process (incorporation of air). When theadhesion and weldability to the reinforcing cord 26 are high, and,furthermore, air entrance into the periphery of the reinforcing cordmember is suppressed, it is possible to effectively suppress themovement of the reinforcing cord 26 due to a force applied or the likewhile travelling. Thereby, for example, even when a tire componentmember has been provided so as to cover the entire outer circumferentialportion of the tire frame with the reinforcing cord member, since themovement of the reinforcing cord member is suppressed, the separation orthe like of the members (including the tire frame) is suppressed, andthe durability of the tire 10 is improved.

In addition, in the tire 10 of the embodiment, since the reinforcingcord 26 having a higher stiffness than the resin material is wound in aspiral shape in the circumferential direction on the outercircumferential surface of the crown portion 16 in the tire case 17formed of the resin material, the puncture resistance, the cuttingresistance and the stiffness of the tire 10 in the circumferentialdirection is improved. Meanwhile, the improvement of the stiffness ofthe tire 10 in the circumferential direction prevents the creeping inthe tire case 17 formed of the thermoplastic resin material.

In addition, in the cross-sectional view of the tire case 17 in theaxial direction (the cross section illustrated in FIG. 1), since atleast some of the reinforcing cord 26 is embedded in the outercircumferential surface of the crown portion 16 in the tire case 17formed of the resin material, and is adhered to the resin material,incorporation of air during manufacturing is suppressed, and themovement of the reinforcing cord 26 due to a force applied or the likewhile travelling is suppressed. Thereby, the separation or the like ofthe reinforcing cord 26, the tire case 17 and a tread 30 is suppressed,and the durability of the tire 10 is improved.

In addition, since the depth L of embedding of the reinforcing cord 26is ⅕ of the diameter D or more as illustrated in FIG. 2, incorporationof air during manufacturing is effectively suppressed, and the movementof the reinforcing cord 26 due to a force applied or the like whiletravelling is further suppressed.

In addition, since the tread 30 that comes into contact with roadsurfaces is configured of a rubber material that has higherabrasion-resistance than the thermoplastic resin material, the abrasionresistance of the tire 10 is improved.

Furthermore, since a circular bead core 18 formed of a metallic materialis embedded in the bead portion 12, similarly to a pneumatic rubber tireof the related art, the tire case 17, that is, the tire 10 is stronglyheld to the rim 20.

In addition, furthermore, since a sealing layer 24 made of a rubbermaterial having higher sealing properties than the resin material isprovided in a portion that comes into contact with the rim 20 of thebead portion 12, the sealing properties between the tire 10 and the rim20 is improved. Therefore, compared to when the tire is sealed with therim 20 using the resin material, the air leakage in the tire is furthersuppressed. In addition, the rim fitting properties is also improved byproviding the sealing layer 24.

The above embodiment employs a configuration in which the reinforcingcord 26 is heated, and the resin material in the portion with which theheated reinforcing cord 26 comes into contact is melted or softened, butthe eighth aspect of the invention is not limited to this configuration,and the reinforcing cord 26 may be embedded in the crown portion 16after heating the outer circumferential surface of the crown portion 16,in which the reinforcing cord 26 is to be embedded, using a hot airgenerating apparatus without heating the reinforcing cord 26.

In addition, in Embodiment 8-1, a heater and a fan are used as the heatsource of a cord heating device 59, but the invention according to theeighth aspect is not limited to this configuration, and a configurationin which the reinforcing cord 26 is directly heated using radiation heat(for example, infrared rays or the like) may be employed. In addition,the reinforcing cord-embedded portion may be melted or softened bymaking the heat source of the hot air generating apparatus, for example,infrared rays converge at the portion at which the reinforcing cord 26is embedded.

Furthermore, Embodiment 8-1 employs a configuration in which theportion, in which the thermoplastic resin material having thereinforcing cord 26 embedded therein is melted or softened, is forciblycooled using the second metal roller 64, but the eighth aspect of theinvention is not limited to this configuration, and a configuration inwhich the portion, in which the thermoplastic resin material is meltedor softened, is forcibly cooled and solidified by directly blowing coldair to the portion in which the thermoplastic resin material is meltedor softened.

In addition, Embodiment 8-1 employs a configuration in which thereinforcing cord 26 is heated; however, for example, a configuration inwhich the outer circumference of the reinforcing cord 26 is coated withthe same thermoplastic resin material as the tire case 17 may beemployed, and, in this case, it is possible to effectively suppressincorporation of air during embedding in the crown portion 16 by heatingthe thermoplastic resin material, which is coated with the reinforcingcord 26, when winding the coated reinforcing cord around the crownportion 16 of the tire case 17.

The tire 10 of Embodiment 8-1 is a so-called tubeless tire in which anair chamber is formed between the tire 10 and the rim 20 by mounting thebead portion 12 in the rim 20, but the eighth aspect of the invention isnot limited to this configuration, and the tire may have a complete tubeshape.

The tire having the complete tube shape may be an aspect in which, forexample, three circular-shaped tire frames are disposed in the tirewidth direction as illustrated in FIG. 4. FIG. 4 is a cross-sectionalview of the tire according to other embodiment. As illustrated in FIG.4, the tire 86 has the tread rubber layer 87, circular-shaped hollowtubes (tire frame) 88 which are made of the same resin material as inEmbodiment 8-1, the belt (reinforcing cord) 89 and the rim 90. Threetubes 88 are disposed in series in the tire width direction of the tire86. The tread rubber layer 87, in which the belt 89 is embedded, isadhered to the outer circumferential portions of the tubes 88. Inaddition, the tubes 88 are mounted on the rim 90 having recess portionsthat engage with the tubes 88. Meanwhile, the bead core is not providedin the tire 86.

In addition, the spiral winding of the reinforcing cord 26 facilitatesthe manufacturing, but a method, in which the reinforcing cord 26 isdiscontinuously formed in the width direction, or the like can be alsoconsidered.

Thus far, an embodiment according to the eighth aspect of the inventionhas been described using the embodiment, but the embodiment is simply anexample, and the invention can be carried out with a variety ofmodifications within the scope of the purport. In addition, it isneedless to say that the scope of right of the invention according tothe eighth aspect is not limited to the above embodiment.

Embodiment 8-2

Next, a method of manufacturing the tire according to the eighth aspectof the invention and Embodiment 8-2 of the tire will be describedaccording to the drawings. Similarly to the above Embodiment 8-1, thetire of the present embodiment exhibits the same cross-sectional shapeas an ordinary pneumatic rubber tire of the related art.

Here, the tire according to Embodiment 8-2 is the same as the aboveEmbodiment 1-2 except for the following facts. Therefore, the samereference signs and drawings will be used in the description regardingthe same drawings and members.

In the tire of Embodiment 8-2, similarly to the above Embodiment 8-1,the tire case 17 is formed of a mixed material of a polyamide-basedthermoplastic elastomer (UBESTA, XPA9048 manufactured by Ube Industries,Ltd.) and an acid-modified polyolefin (ADOMER QE060 manufactured byMitsui Chemicals, Inc., a glass transition temperature 4° C.)(hereinafter referred to simply as “resin material” in the descriptionof Embodiment 8-2). Other portions are the same as in the tire accordingto the above Embodiment 1-2, and the manufacturing method is also thesame.

(Effects)

In the tire 200 of the embodiment, since the tire case 17 is formed ofthe resin material further including the specific resin according to theeighth aspect of the invention having a glass transition temperature inthe above range in addition to the thermoplastic elastomer, a favorableelastic modulus can be obtained in the tire case 17, and an increase inthe rolling resistance of the tire can be suppressed.

In the method of manufacturing the tire of the embodiment, when the tirecase 17, the cushion rubber 29 and a tread rubber 30A are integrated,since the outer circumferential surface 17S of the tire case 17 has beentreated to be coarse, the bonding properties (adhesion) is improved dueto the anchor effect. In addition, since the resin material that formsthe tire case 17 is dug out by the collision of a blasting abrasive, thewettability of a bond is improved. Thereby, a state in which the bond isuniformly coated on the outer circumferential surface 17S of the tirecase 17 is held, and the bonding strength between the tire case 17 andthe cushion rubber 29 can be ensured.

Particularly, even when protrusions and recesses are formed on the outercircumferential surface 17S of the tire case 17, the peripheries of therecess portions (recess walls and recess bottoms) are treated to becoarse by making the blasting abrasive collide with the recess portions(voids 28A), and the bonding strength between the tire case 17 and thecushion rubber 29 can be ensured.

Meanwhile, since the cushion rubber 29 is laminated in thecoarsening-treated areas on the outer circumferential surface 17S of thetire case 17, the bonding strength between the tire case 17 and thecushion rubber 29 can be effectively ensured.

When the cushion rubber 29 has been vulcanized in the vulcanizingprocess, the cushion rubber 29 flows into the coarsened recesses andprotrusions formed on the outer circumferential surface 17S of the tirecase 17 through the coarsening treatment. In addition, whenvulcanization is completed, the anchor effect is developed due to thecushion rubber 29 that has flowed into the coarsened recesses andprotrusions so that the bonding strength between the tire case 17 andthe cushion rubber 29 is improved.

In the tire 200 manufactured using the above method of manufacturing atire, the bonding strength between the tire case 17 and the cushionrubber 29 is ensured, that is, the bonding strength between the tirecase 17 and the tread 30 is ensured through the cushion rubber 29.Thereby, the separation between the outer circumferential surface 17S ofthe tire case 17 of the tire 200 and the cushion rubber 29 is suppressedwhile travelling and the like.

In addition, since the outer circumferential portion of the tire case 17is configured of the reinforcing cord layer 28, the puncture resistanceand the cutting resistance improve compared to a tire case having theouter circumferential portion configured of something other than thereinforcing cord layer 28.

In addition, since the reinforcing cord layer 28 is formed by windingthe coated cord member 26B, the stiffness of the tire 200 in thecircumferential direction is improved. The improvement of the stiffnessin the circumferential direction suppresses creeping (a phenomenon inwhich the plastic deformation of the tire case 17 increases over timeunder a constant stress) in the tire case 17, and the pressureresistance with respect to the air pressure from the inside in the tirediameter direction is improved.

In the embodiment, the recesses and protrusions are configured on theouter circumferential surface 17S of the tire case 17, but the inventionaccording to the eighth aspect is not limited thereto, and aconfiguration in which the outer circumferential surface 17S is formedto be flat may be employed.

In addition, in the tire case 17, the reinforcing cord layer may beformed by covering the coated cord member, which is wound around andbonded to the crown portion of the tire case, with a thermoplasticmaterial for coating. In this case, a coated layer can be formed bydischarging a thermoplastic material for coating in a molten or softenedstate on the reinforcing cord layer 28. In addition, the coated layermay be formed by heating an adhesive sheet into a molten or softenedstate without using an extruder, and attaching the adhesive sheet to thesurface (outer circumferential surface) of the reinforcing cord layer28.

The above Embodiment 8-2 employs a configuration in which partitionedcase bodies (tire case half parts 17A) are bonded so as to form the tirecase 17, but the eighth aspect of the invention is not limited thereto,and the tire case 17 may be integrally formed using a mold or the like.

The tire 200 of Embodiment 8-2 is a so-called tubeless tire in which anair chamber is formed between the tire 200 and the rim 20 by mountingthe bead portion 12 in the rim 20, but the eighth aspect of theinvention is not limited to this configuration, and the tire 200 mayhave, for example, a complete tube shape.

In Embodiment 8-2, the cushion rubber 29 is disposed between the tirecase 17 and the tread 30, but the invention according to the eighthaspect is not limited thereto, and a configuration in which the cushionrubber 29 is not disposed may be employed.

In addition, Embodiment 8-2 employs a configuration in which the coatedcord member 26B is wound around the crown portion 16 in a spiral shape,but the eighth aspect of the invention is not limited thereto, and aconfiguration in which the coated cord member 26B is discontinuouslyformed in the width direction may be employed.

Embodiment 8-2 employs a configuration in which a thermoplastic materialis used as the resin material for coating 27 that forms the coated cordmember 26B, and the resin material for coating 27 is heated into amolten or softened state so as to weld the coated cord member 26B on theouter circumferential surface of the crown portion 16, but the eighthaspect of the invention is not limited to this configuration, and aconfiguration in which the coated cord member 26B is adhered on theouter circumferential surface of the crown portion 16 using an adhesiveor the like without heating the resin material for coating 27 may beemployed.

In addition, a configuration in which a thermosetting resin is used asthe resin material for coating 27 that forms the coated cord member 26B,and the coated cord member 26B is adhered on the outer circumferentialsurface of the crown portion 16 using an adhesive or the like withoutheating may be employed.

Furthermore, a configuration in which a thermosetting resin is used asthe resin material for coating 27 that forms the coated cord member 26Band the tire case 17 is formed of a thermoplastic resin material may beemployed. In this case, the coated cord member 26B may be adhered to theouter circumferential surface of the crown portion 16 using an adhesiveor the like, or the coated cord member 26B may be welded on the outercircumferential surface of the crown portion 16 by heating into a moltenor softened state the portion at which the coated cord member 26B of thetire case 17 is provided.

In addition, furthermore, a configuration in which a thermoplasticmaterial is used as the resin material for coating 27 that forms thecoated cord member 26B and the tire case 17 is formed of a thermoplasticresin material. In this case, the coated cord member 26B may be adheredto the outer circumferential surface of the crown portion 16 using anadhesive or the like, or the coated cord member 26B may be welded on theouter circumferential surface of the crown portion 16 by heating into amolten or softened state the portion at which the coated cord member 26Bof the tire case 17 is provided, and heating the resin material forcoating 27 into a molten or softened state. Meanwhile, when both thetire case 17 and the coated cord member 26B have been heated into amolten or softened state, since both are well mixed, the bondingstrength is improved. In addition, when thermoplastic resin materialsare used as both the resin material that forms the tire case 17 and theresin material for coating 27 that forms the coated cord member 26B, thethermoplastic resin materials are preferably the same kind ofthermoplastic materials, particularly, the same thermoplastic material.

In addition, furthermore, an adhesive may be coated on the outercircumferential surface 17S of the tire case 17, on which the coarseningtreatment has been carried out, after the surface of the outercircumferential surface 17S is activated using a corona treatment, aplasma treatment or the like so as to increase the hydrophilicity.

In addition, furthermore, the order for manufacturing the tire 200 isnot limited to the order in Embodiment 8-1, and may be appropriatelychanged.

Thus far, an embodiment according to the eighth aspect of the inventionhas been described using the embodiment, but the embodiment is simply anexample, and the invention can be carried out with a variety ofmodifications within the scope of the purport. In addition, it isneedless to say that the scope of right of the invention according tothe eighth aspect is not limited to the above embodiment.

Thus far, the specific aspects of the invention according to the eighthaspect have been described using Embodiment 8-1 and Embodiment 8-2, butthe invention according to the eighth aspect is not limited to the aboveaspects.

<<Ninth Aspect of the Invention>>

Next, a resin material constituting as a component of a tire frameaccording to a ninth aspect of the invention will be described, and,subsequently, a specific embodiment of the tire according to the ninthaspect of the invention will be described using the drawings.

[Resin Material]

The tire according to the ninth aspect of the invention is a tireincluding at least a circular tire frame formed of a resin material, inwhich the resin material includes at least a first thermoplasticelastomer, a resin which is other than the first thermoplastic elastomerand has a glass transition temperature of 20° C. or lower (the specificresin according to the ninth aspect of the invention), and a secondthermoplastic elastomer which is other than the first thermoplasticelastomer and includes a hard segment of the same kind as the resin. Theelastic modulus of the resin (the specific resin according to the ninthaspect of the invention) is preferably larger than the elastic modulusof the first thermoplastic elastomer. In addition, the elastic modulusof the second thermoplastic elastomer is preferably smaller than theelastic modulus of the resin.

When the second thermoplastic elastomer having the above configurationis further included in addition to the first thermoplastic elastomer andthe specific resin according to the ninth aspect of the invention as theresin material constituting as a component of the circular tire framethat forms the tire, the impact resistance of the tire is improved.

Hereinafter, the first thermoplastic elastomer, the specific resinaccording to the ninth aspect of the invention, and the secondthermoplastic elastomer will be described.

[First Thermoplastic Elastomer]

The “thermoplastic elastomer” refers to a resin material including ahard segment and a soft segment in a molecule thereof as describedabove, and, in detail, to a resin material which is an elasticmacromolecular compound and is formed of a copolymer having a polymerconstituting a hard segment that is crystalline and has a high meltingpoint or a hard segment forming a pseudo-crosslink through physicalagglomeration, and a polymer constituting a segment that isnon-crystalline and has a low glass transition temperature. Meanwhile,the first thermoplastic elastomer includes vulcanized rubber, such asnatural rubber or synthetic rubber of the related art.

Examples of the first thermoplastic elastomer include polyamide-basedthermoplastic elastomers, polyester-based thermoplastic elastomer,polyurethane-based thermoplastic elastomers, polystyrene-basedthermoplastic elastomers and the like.

(Polyamide-Based Thermoplastic Elastomer)

The “polyamide-based thermoplastic elastomer” is an elasticmacromolecular compound, and refers to a resin material which is formedof a copolymer having a polymer constituting a hard segment that iscrystalline and has a high melting point, and a polymer constituting asoft segment that is non-crystalline and has a low glass transitiontemperature, and has an amid bond (—CONH—) in the main chain of thepolymer constituting the hard segment.

Examples of crystalline polyamide as a component of the hard segmentinclude aliphatic amides, such as polycaproamide (nylon-6),poly-ω-aminoheptanoic acid (nylon-7), poly-ω-aminononanoic acid(nylon-9), polyundecaneamide (nylon-11), polylauryl lactam (nylon-12),polyethylene diamine adipamide (nylon-2,6), polytetramethylene adipamide(nylon-4,6), polyhexamethylene adipamide (nylon-6,6), polyhexamethylenesebacamide (nylon-6,10), polyhexamethylene dodecamide (nylon-6,12),polyoctamethylene adipamide (nylon-8,6) and polydecamethylene adipamide(nylon-10,8); crystalline aromatic polyamides obtained through apolycondensation reaction between an aromatic diamine, such asmeta-xylene diamine or para-xylene diamine, and a dicarboxylic acid,such as adipic acid, suberic acid, sebacic acid, cyclohexanedicarboxylic acid, terephthalic acid or isophthalic acid, or aderivative thereof; and the like.

Among the above, nylon-6, nylon-6,6, nylon-12 and the like arepreferable, and nylon-12 is more preferable. As the “polyamide-basedthermoplastic elastomer” in the present embodiment, the samepolyamide-based thermoplastic elastomer as in the invention according tothe above first aspect can be used.

(Polyurethane-Based Thermoplastic Elastomer)

The “polyurethane-based thermoplastic elastomer” is an elasticmacromolecular compound, and refers to a resin material which is formedof a copolymer having a polymer as a component of the hard segmentforming a pseudo-crosslink through physical agglomeration and a polymerconstituting the soft segment that is non-crystalline and has a lowglass transition temperature, and has a urethane bond in the main chainof the polymer as a component of the hard segment. The“polyurethane-based thermoplastic elastomer” in the embodiment is thesame as in the above second aspect of the invention.

(Polystyrene-Based Thermoplastic Elastomer)

The “polystyrene-based thermoplastic elastomer” is an elasticmacromolecular compound, and examples thereof include a material inwhich at least a polystyrene constitutes the hard segment, and anotherpolymer (for example, polybutadiene, polyisoprene, polyethylene,hydrogenated polybutadiene, hydrogenated polyisoprene, or the like)constitutes the soft segment that is non-crystalline and has a low glasstransition temperature. The “polyolefin-based thermoplastic elastomer”in the embodiment is the same as in according to the above second aspectof the invention.

(Polyester-Based Thermoplastic Elastomer)

Examples of the polyester-based thermoplastic elastomer include at leasta material in which a polyester constitutes the hard segment that iscrystalline and has a high melting point, and another polymer (forexample, polyester, polyether, or the like) constitutes the soft segmentthat is non-crystalline and has a low glass transition temperature. The“polyester-based thermoplastic elastomer” in the embodiment is the sameas in the above second aspect of the invention.

The resin material according to the ninth aspect of the invention mayinclude two or more kinds of the first thermoplastic elastomers, but thethermoplastic resin material preferably includes one kind of the firstthermoplastic elastomer from the viewpoint of controlling tireperformances of a tire formed using the resin material.

Among the first thermoplastic elastomers described above, at least oneselected from the polyamide-based thermoplastic elastomers, thepolyester-based thermoplastic elastomer, the polyurethane-basedthermoplastic elastomers and the polystyrene-based thermoplasticelastomers is preferably used, and, furthermore, the polyamide-basedthermoplastic elastomer or the polyester-based thermoplastic elastomeris preferable since the polyamide-based thermoplastic elastomer or thepolyester-based thermoplastic elastomer has thermal resistance and isexcellent in term of tensile modulus of elasticity, tensile strength andfracture strain, the structure of the tire can be simplified compared toa rubber tire of the related art, and, consequently, reduction in weightof the tire can be realized.

Further, the glass transition temperature (Tg) of the firstthermoplastic elastomer is preferably from 30° C. to 50° C., and morepreferably from 25° C. to 70° C. in order to decrease the influence onthe rolling resistance, that is, in order to suppress the tan δ at 30°C. to 50° C. The glass transition temperature can be measured inaccordance with the same method as for the glass transition temperaturein a specific resin according to the ninth aspect of the inventiondescribed below.

In addition, the elastic modulus of the first thermoplastic elastomer islower than the elastic modulus of the specific resin according to theninth aspect of the invention since the elastic modulus of the firstthermoplastic elastomer is increased by adding the specific resinaccording to the ninth aspect of the invention, is preferably from 5 MPato 700 MPa, and more preferably from 10 MPa to 500 MPa. The elasticmodulus refers to the tensile modulus of elasticity regulated in JISK7113:1995, and can be measured using, for example, a precisionuniversal tester AUTOGRAPH manufactured by Shimadzu Corporation.

In addition, the tan δ of the first thermoplastic elastomer ispreferably from 0 to 0.1, and more preferably from 0 to 0.07 in order tosuppress the tan δ at 30° C. to 50° C. The tan δ can be measured using,for example, ARESIII manufactured by Rheometric Scientific, Inc. underthe conditions of 30° C., 20 Hz and 1% of shear distortion.

[The Specific Resin According to the Ninth Aspect of the Invention]

The resin material includes a resin which has a glass transitiontemperature of 20° C. or lower and is other than the first thermoplasticelastomer (the specific resin according to the ninth aspect of theinvention).

Further, the resin according to the ninth aspect of the invention refersto a thermoplastic or thermosetting resin, and does not encompassvulcanized rubber, such as natural rubber or synthetic rubber of therelated art.

The glass transition temperature (Tg) is more preferably 15° C. orlower, and particularly preferably 10° C. or lower. Further, the lowerlimit value is not particularly limited, but the glass transitiontemperature is preferably equal to or greater than −200° C., andparticularly preferably equal to or greater than −150° C.

When the specific resin according to the ninth aspect of the inventionhaving a glass transition temperature of the upper limit value or lessis added to the thermoplastic elastomer, and used, the resin materialhas a desired elastic modulus, and the tan δ can be suppressed at a lowlevel. As a result, in the ninth aspect of the invention t, a preferableelastic modulus can be obtained, and the rolling resistance of the tirecan be reduced.

Here, the glass transition temperature of the specific resin accordingto the ninth aspect of the invention can be measured from thetemperature dependency of the dynamic loss (tan δ). For example, theglass transition temperature can be measured using, for example, ARESIIImanufactured by Rheometric Scientific, Inc. under the conditions of 10Hz and 0.2% of shear distortion. Alternatively, the glass transitiontemperature can be measured using a differential scanning calorimetry(DSC).

As the specific resin according to the ninth aspect of the invention,for example, among the resins listed as examples of the resin which isnot modified by an acid (other resin) described below, resins satisfyingthe glass transition temperature (Tg) or acid-modified resins describedbelow can be used.

Further, the specific resin according to the ninth aspect of theinvention is more preferably an acid-modified resin. The “acid-modifiedresin” refers to a resin obtained by bonding an unsaturated compoundhaving an acidic group, such as a carboxylic acid group, a sulfuric acidgroup or a phosphoric acid group, to a resin. For example, when anunsaturated carboxylic acid group (generally, maleic acid anhydride) isused as the unsaturated compound having an acidic group, an unsaturatedbond portion of the unsaturated carboxylic acid is bonded (for example,graft polymerization) to an olefin-based resin.

When the acid-modified resin is used, the resin material includes asea-island structure having a sea phase constituted of a thermoplasticelastomer and an island phase constituted of the acid-modified resin.When the interaction at the phase interface between the sea phase andthe island phase is weak, the fluidity of the resin material increasesand the injection moldability is excellent. Since the acid-modifiedresin has an acid-modified portion in a molecule thereof, theinteraction with the thermoplastic elastomer is strong, compared to aresin that is not modified by an acid.

The acid-modified resin is preferably a compound having a carboxylicacid group, which is a weak acid group, from the viewpoint ofsuppressing the deterioration of the thermoplastic elastomer, andexamples thereof include acrylic acid, methacrylic acid, itaconic acid,crotonic acid, isocrotonic acid, maleic acid, and the like.

Examples of the acid-modified resin include an acid-modified polyolefinresin and the like. Among the above, acid-modified polyethylene,acid-modified polypropylene, acid-modified ethylene-propylenecopolymers, ethylene-vinyl acetate copolymers are preferable.

Examples of the acid-modified polyolefin include ADOMER QF551, QE060,LB548, NE827, QB550 and the like manufactured by Mitsui Chemicals, Inc.

The acid value of the acid-modified resin needs to exceed 0 mg(CH₃ONa)/g. The acid value is measured as the mass [mg] of sodiummethoxide (CH₃ONa) used when neutralization titration is carried out onthe respective acid-modified resin 1 [g] using sodium methoxide(CH₃ONa).

Hereinafter, the units of the acid values of the respectiveacid-modified resins will also be expressed using [mg(CH₃ONa)/g].

In the sea-island structure, there is a tendency for the island phase tobecome smaller as the acid value increases, and there is a tendency forthe island phase to become large as the acid value decreases. Byincluding the acid-modified resin, the island phase is finely dispersedin the thermoplastic elastomer.

Meanwhile, the island phase of the acid-modified resin finely dispersedin the resin material can be confirmed through photograph observationusing SEM (scanning electron microscope).

Further, the elastic modulus of the specific resin according to theninth aspect of the invention is higher than the elastic modulus of thethermoplastic elastomer, in order to increase the elastic modulus, ispreferably 100 MPa to 3000 MPa, and more preferably 300 MPa to 2000 MPa.The elastic modulus refers to the tensile modulus of elasticityregulated in JIS K7113:1995, and can be measured using the methoddescribed in the above thermoplastic elastomer.

In addition, the tan δ of the specific resin according to the ninthaspect of the invention preferably has a peak of the tan δ at −150° C.to 20° C., and more preferably has a peak at −150° C. to 15° C. in orderto decrease the tan δ of the resin material. The tan δ can be measuredusing the method described in the above thermoplastic elastomer.

Further, the resin material may include two or more kinds of thespecific resin according to the ninth aspect of the invention.

[Second Thermoplastic Elastomer]

The resin material includes the second thermoplastic elastomer whichincludes a hard segment of the same kind as the resin material and isother than the first thermoplastic elastomer.

The “thermoplastic elastomer including a hard segment of the same kindas the resin” refers to a thermoplastic elastomer including a hardsegment including a skeleton which is common to the skeletonconstituting the main chain of the resin.

It is considered that, when the second thermoplastic elastomer includesthe hard segment including a skeleton which is common to the skeletonthat constitutes the main chain of the specific resin according to theninth aspect of the invention, the affinity between the specific resinaccording to the ninth aspect of the invention and the hard segment ofthe second thermoplastic elastomer increases.

In addition, it is considered that, when the second thermoplasticelastomer is further included in addition to the first thermoplasticelastomer and the specific resin according to the ninth aspect of theinvention, flexibility is given to the specific resin according to theninth aspect of the invention, and, consequently, the impact resistanceof the resin material is improved.

When the rein material contains the specific resin according to theninth aspect and, furthermore, a resin which is not modified by an acid(other resin) described below, as the second thermoplastic elastomer, itis preferable to use a second thermoplastic elastomer including a hardsegment of the same kind as the other resin, that is, the secondthermoplastic elastomer including a hard segment with a skeleton whichis common to the skeleton that constitutes the main chain of the otherresin.

For example, when the specific resin according to the ninth aspect ofthe invention, which is included in the resin material, is aolefin-based resin, and the other resin is polypropylene, anolefin-based thermoplastic elastomer including polypropylene as thesecond thermoplastic elastomer is preferably used.

As described above, since an acid-modified polyolefin is preferably usedas the specific resin according to the ninth aspect of the invention,which is included in the resin material, the second thermoplasticelastomer is preferably an olefin-based thermoplastic elastomer.

Further, the glass transition temperature (Tg) of the secondthermoplastic elastomer is not particularly limited, but is preferablyequal to or less than 30° C., or equal to or greater than 50° C., andmore preferably equal to or less than 25° C., or equal to or greaterthan 70° C. in order to decrease the influence on the rollingresistance, that is, to suppress the tan δ at 30° C. to 50° C. The glasstransition temperature can be measured in accordance with the samemethod as for the glass transition temperature in the specific resinaccording to the ninth aspect of the invention described above.

Here, the glass transition temperature can be measured from, forexample, the temperature dependency of the dynamic loss (tan δ). Forexample, the glass transition temperature can be measured using, forexample, ARESIII manufactured by Rheometric Scientific, Inc. under theconditions of 10 Hz and 0.2% of shear distortion. Alternatively, theglass transition temperature can be measured using a differentialscanning calorimetry (DSC).

In addition, the elastic modulus of the second thermoplastic elastomeris lower than the elastic modulus of the specific resin according to theninth aspect of the invention, is preferably from 5 MPa to 700 MPa, andmore preferably from 10 MPa to 500 MPa. The elastic modulus refers tothe tensile modulus of elasticity regulated in JIS K7113:1995, and canbe measured using, for example, a precision universal tester AUTOGRAPHmanufactured by Shimadzu Corporation.

An olefin-based thermoplastic elastomer is preferable as the secondthermoplastic elastomer.

(Polyolefin-Based Thermoplastic Elastomer)

Examples of the “polyolefin-based thermoplastic elastomer” include atleast a material in which a polyolefin constitutes the hard segment thatis crystalline and has a high melting point, and another polymer (forexample, the above polyolefin, other polyolefin or crosslinked rubber)constitutes the soft segment that is non-crystalline and has a low glasstransition temperature. Examples of the polyolefin that forms the hardsegment include polyethylene, polypropylene, isotactic polypropylene,polybutene, and the like. The “polyolefin-based thermoplastic elastomer”in the embodiment is the same as in the above second aspect of theinvention.

As the polyolefin-based thermoplastic elastomer, for example,commercially available products such as “TAFMER” series manufactured byMitsui Chemicals, Inc. (for example, A0550S, A1050S, A4050S, A1070S,A4070S, A35070S, A1085S, A4085S, A7090, A70090, MH7007, MH7010, XM-7070,XM-7080, BL4000, BL2481, BL3110, BL3450, P-0275, P-0375, P-0775, P-0180,P-0280, P-0480 and P-0680), “NUCREL” series manufactured by DuPont-Mitsui Polychemicals Co., Ltd. (for example, AN4214C, AN4225C,AN42115C, N0903HC, N0908C, AN42012C, N410, N1050H, N1108C, N1110H,N1207C, N1214, AN4221C, N1525, N1560, N0200H, AN4228C, AN4213C andN035C, “ELVALOY AC” series (for example, 1125AC, 1209AC, 1218AC, 1609AC,1820AC, 1913AC, 2112AC, 2116AC, 2615AC, 2715AC, 3117AC, 3427AC and3717AC), “ACRIFT” series, “EVATATE” series manufactured by SumitomoChemical Company, Limited, “ULTRASEN” series manufactured by TosohCorporation, and the like, can be used.

Furthermore, as the polyolefin-based thermoplastic elastomer examples,for example, commercially available products such as “PRIME TPO” seriesmanufactured by Prime Polymer Co., Ltd. (for example, E-2900H, F-3900H,E-2900, F-3900, J-5900, E-2910, F-3910, J-5910, E-2710, F-3710, J-5910,E-2740, F-3740, R110MP, R110E, T310E, M142E and the like) also can beused.

TPV is a polyolefin-based thermoplastic elastomer obtained byincorporating rubber, such as EPR or EPDM, and a crosslinking agent intoan olefin resin, such as propylene, and carrying out crosslinking whilekneading the components using a biaxial extruder. Generally incorporatedadd-in materials, such as oil and an antioxidant, may be incorporatedinto rubber.

As the polyolefin-based thermoplastic elastomer, for examples,commercially available products such as MILASTOMER (registeredtrademark) manufactured by Mitsui Chemicals, Inc., ESPOLEX TPE seriesmanufactured by Sumitomo Chemical Company, Limited, THERMORUN(registered trademark) manufactured by Mitsubishi Chemical Corporationand the like can be used.

[Resin which is not Modified by Acid (Other Resin)]

When the resin material includes the acid-modified resin as the specificresin according to the ninth aspect of the invention, the resin materialmay further include a resin which is not modified by an acid (otherresin), and which is other than the first thermoplastic elastomer andthe second thermoplastic elastomer. The resin which is not modified byacid refers to a resin having an average rate of acid modification of 0mg/g.

Further, the resin in the ninth aspect of the invention refers to athermoplastic or thermosetting resin, and does not include vulcanizedrubber, such as natural rubber or synthetic rubber of the related art.

As such, when the resin material contains the first thermoplasticelastomer, the acid-modified specific resin according to the ninthaspect of the invention, the second thermoplastic elastomer, and,furthermore, the resin which is not modified by an acid (other resin),the tensile characteristics, such as tensile elasticity and rupturestrength, can be improved as the tire performances.

In addition, when the resin material does not include the acid-modifiedresin as the specific resin according to the ninth aspect of theinvention, the resin material may include the resin which is notmodified by an acid (other resin, which satisfies the conditions of thespecific resin according to the ninth aspect of the invention) as thespecific resin according to the ninth aspect of the invention. Further,when the thermoplastic elastomer is a polystyrene-based thermoplasticelastomer, since a polar group is not included in the polystyrene-basedthermoplastic elastomer, the resin which is not modified by an acid ispreferably used as the specific resin according to the ninth aspect ofthe invention.

Examples of the other resin include polyolefin resins and the like.Among the above, polypropylene, polyethylene, ethylene-propylenecopolymers, and the like can be exemplified, and polypropylene andethylene-propylene copolymers are preferable particularly from theviewpoint of improving the tensile characteristics, such as tensileelasticity and rupture strength.

Examples of the polypropylene and the ethylene-propylene copolymersinclude J-700GP (homopolymer), JP-2000GP (homopolymer), J-466HP (blockpolymer), J-106MG (homopolymer), J-226T (random polymer) manufactured byPrime Polymer Co., Ltd.; NOVATEC EC9EV (block polymer), Wintec WFW4(random polymer) manufactured by Japan Polypropylene Corporation, andthe like.

In addition, the tan δ of other resin preferably has a peak of the tan δat −150° C. to 20° C., and more preferably has a peak at −150° C. to 15°C. in order to decrease the tan δ of the resin material. The tan δ canbe measured using the method described in the above thermoplasticelastomer.

Further, when the resin material contains the thermoplastic elastomer,the acid-modified specific resin according to the ninth aspect of theinvention, and, furthermore, the resin which is not modified by an acid(other resin), the tan δ of other resin is not particularly limited inthe above range.

In addition, the elastic modulus of the other resin is higher than theelastic modulus of the thermoplastic elastomer, in order to increase theelastic modulus, is preferably from 100 MPa to 3000 MPa, and morepreferably from 300 MPa to 2000 MPa. The elastic modulus refers to thetensile modulus of elasticity regulated in JIS K7113:1995, and can bemeasured using the method described in the above thermoplasticelastomer.

Further, the resin material may include two or more kinds of the otherresin.

[Combination and Ratio]

In the resin material according to the ninth aspect of the invention,the ratio of the total amount of the specific resin according to theninth aspect of the invention and the other resin to the firstthermoplastic elastomer (the first thermoplastic elastomer:the specificresin according to the ninth aspect of the invention+the other resin[mass ratio]) is preferably from 95:5 to 55:45, and more preferably from95:5 to 60:40 from the viewpoint of making the first thermoplasticelastomer form a sea phase in the sea-island structure.

In addition, when both the specific resin according to the ninth aspectof the invention and the other resin are included, the ratio of theother resin to the specific resin according to the ninth aspect of theinvention (the specific resin according to the ninth aspect of theinvention:the other resin [mass ratio]) is preferably from 100:0 to5:95, and more preferably from 100:0 to 10:90 from the viewpoint ofproviding the interaction with the thermoplastic elastomer.

In addition, the ratio of the second thermoplastic elastomer to thetotal amount of the specific resin according to the ninth aspect of theinvention and the other resin (the specific resin according to the ninthaspect of the invention+the other resin:the second thermoplasticelastomer [mass ratio]) is preferably from 95:5 to 50:50 from theviewpoint of dispersing the second thermoplastic elastomer in thespecific resin according to the ninth aspect of the invention and theother resin.

Furthermore, the total content of the thermoplastic elastomer, the firstthermoplastic elastomer, the specific resin according to the ninthaspect of the invention, the second thermoplastic elastomer, and theother resin in the resin material is preferably 50 mass % to 100 mass %with respect to the total mass of the resin material from the viewpointof making the thermoplastic elastomer, the first thermoplasticelastomer, the specific resin according to the ninth aspect of theinvention, the second thermoplastic elastomer, and the other resin forma sea phase in the sea-island structure.

Further, the combination of the thermoplastic elastomer, the specificresin according to the ninth aspect of the invention, and the otherresin in the resin material according to the ninth aspect of theinvention is preferably the following combination.

-   -   A combination of the polyamide-based thermoplastic elastomer,        the acid-modified polyolefin resin and the olefin-based        thermoplastic elastomer    -   A combination of the polyamide-based thermoplastic elastomer,        the acid-modified polyolefin resin, polypropylene and the        olefin-based thermoplastic elastomer including polypropylene    -   A combination of the polyamide-based thermoplastic elastomer,        the acid-modified polyolefin resin, an ethylene-propylene        copolymer and the olefin-based thermoplastic elastomer including        polypropylene    -   A combination of the polyester-based thermoplastic elastomer,        the acid-modified polyolefin resin and the olefin-based        thermoplastic elastomer    -   A combination of the polyester-based thermoplastic elastomer,        the acid-modified polyolefin resin, polypropylene and the        olefin-based thermoplastic elastomer including polypropylene    -   A combination of the polyester-based thermoplastic elastomer,        the acid-modified polyolefin resin, an ethylene-propylene        copolymer and the olefin-based thermoplastic elastomer including        polypropylene    -   A combination of the polystyrene-based thermoplastic elastomer,        the polyolefin resin and the olefin-based thermoplastic        elastomer

[Other Compositions and the Properties of the Resin Material]

The resin material may contain a variety of fillers (for example,silica, calcium carbonate and clay) and a variety of additives, such asan age inhibitor, oil, a plasticizer, a coloring agent, aweather-resisting agent and a reinforcing material, as desired.

The resin material can be obtained by mixing the first thermoplasticelastomer, the specific resin according to the ninth aspect of theinvention and the second thermoplastic elastomer, adding other resin ora variety of additives as necessary, and melting and mixing thecomponents. The mixing proportion among the first thermoplasticelastomer, the specific resin according to the ninth aspect of theinvention and the second thermoplastic elastomer follows the fractionsdescribed above. The resin material obtained through melting and mixingcan be used in a pellet shape as necessary.

The tensile modulus of elasticity of the resin material according to theninth aspect of the invention, which is regulated in JIS K7113:1995, ispreferably from 100 MPa to 1000 MPa, more preferably from 100 MPa to 800MPa, and particularly preferably from 100 MPa to 700 MPa. When thetensile modulus of elasticity of the resin material is 100 MPa to 1000MPa, fitting onto a rim can be efficiently carried out while holding theshape of the tire frame.

The tensile yield strength of the resin material according to the ninthaspect of the invention, which is regulated in JIS K7113:1995, ispreferably 5 MPa or more, preferably from 5 MPa to 20 MPa, and stillmore preferably from 5 MPa to 17 MPa. When the tensile yield strength ofthe resin material is 5 MPa or more, it is possible to withstanddeformation caused by a load applied to the tire while travelling andthe like.

The tensile yield elongation of the resin material according to theninth aspect of the invention, which is regulated in JIS K7113:1995, ispreferably 10% or more, preferably from 10% to 70%, and still morepreferably from 15% to 60%. When the tensile yield elongation of theresin material is 10% or more, it is possible to increase the elasticarea and improve fittability onto a rim.

The tensile fracture elongation of the resin material according to theninth aspect of the invention, which is regulated in JIS K7113:1995, ispreferably equal to or greater than 50%, preferably equal to or greaterthan 100%, still more preferably equal to or greater than 150%, andparticularly preferably equal to or greater than 200%. When the tensilefracture elongation of the resin material is equal to or greater than50%, it is possible to improve the fittability onto a rim and make theresin material resistant to fracture due to collision.

The deflection temperature under load (under a load of 0.45 MPa) of theresin material according to the ninth aspect of the invention, which isregulated in ISO75-2 or ASTM D648, is preferably equal to or greaterthan 50° C., preferably from 50° C. to 150° C., and still morepreferably from 50° C. to 130° C. When the deflection temperature underload of the resin material is equal to or greater than 50° C., it ispossible to suppress deflection in a curing step, such as treading.

[Resin Material as a Component of the Reinforcing Cord Layer]

The tire according to the ninth aspect of the invention may have thereinforcing cord member which is wound around the outer circumferentialsurface of the tire frame in the circumferential direction so as to formthe reinforcing cord layer.

The “resin material as a component of the reinforcing cord layer”according to the ninth aspect of the invention are the same as the“resin material as a component of the reinforcing cord layer” accordingto the first aspect of the invention.

Embodiment 9-1

Hereinafter, a tier according to Embodiment 9-1 of the tire according tothe ninth aspect of the invention will be described according to thedrawings.

Here, the tire according to Embodiment 9-1 is the same as the aboveEmbodiment 1-1 except for the following facts. Therefore, the samereference signs and drawings will be used in the description regardingthe same drawings and members.

The tire case 17 of the embodiment is formed of a resin materialcontaining a polyamide-based thermoplastic elastomer (UBESTA, XPA9048manufactured by Ube Industries, Ltd.), an acid-modified polyolefin(ADOMER QF551 manufactured by Mitsui Chemicals, Inc., a glass transitiontemperature −13° C.) and an olefin-based thermoplastic elastomerincluding polypropylene (PRIME TPO F-3740 manufactured by Prime PolymerCo., Ltd.) (hereinafter referred to simply as “resin material” in thedescription of Embodiment 9-1). In the present embodiment, the tire case17 is formed of a single kind of a resin material, the inventionaccording to the ninth aspect is not limited to this configuration, and,similarly to an ordinary pneumatic rubber tire of the related art,different thermoplastic resin materials having different characteristicsmay be used in the respective portions (the side portions 14, the crownportion 16, the bead portions 12, and the like) of the tire case 17.Other portions are the same as in the tire according to the aboveEmbodiment 1-1, and the manufacturing method is the same as well.

(Effects)

In the tire 10 of the embodiment, since the tire case 17 is formed ofthe resin material further including the second thermoplastic elastomerin addition to the first thermoplastic elastomer and the specific resinaccording to the ninth aspect of the invention, the elastic modulus ofthe tire case 17 can be controlled, and an increase in the rollingresistance of the tire can be suppressed.

In addition, the resin material has a high adhesion to the reinforcingcord 26, and, furthermore, is excellent in terms of fixing performances,such as weld strength. Therefore, it is possible to suppress thephenomenon in which air remains around the reinforcing cord 26 in thereinforcing cord winding step (incorporation of air). When the adhesionand weldability to the reinforcing cord 26 are high, and, furthermore,incorporation of air into the periphery of the reinforcing cord memberis suppressed, it is possible to effectively suppress the movement ofthe reinforcing cord 26 due to, for example, a force applied whiletravelling. Thereby, for example, even when a tire-constituting memberhas been provided so as to cover the entire outer circumferentialportion of the tire frame with the reinforcing cord member, since themovement of the reinforcing cord member is suppressed, the separation orthe like of the members (including the tire frame) is suppressed, andthe durability of the tire 10 is improved.

In addition, in the tire 10 of the embodiment, since the reinforcingcord 26 having a higher stiffness than the resin material is wound in aspiral shape in the circumferential direction on the outercircumferential surface of the crown portion 16 in the tire case 17formed of the resin material, the puncture resistance, the cuttingresistance and the stiffness of the tire 10 in the circumferentialdirection are improved. Meanwhile, the improvement of the stiffness ofthe tire 10 in the circumferential direction prevents the creeping inthe tire case 17 formed of the thermoplastic resin material.

In addition, in the cross-sectional view of the tire case 17 in theaxial direction (the cross section illustrated in FIG. 1), since atleast some of the reinforcing cord 26 is embedded in the outercircumferential surface of the crown portion 16 in the tire case 17formed of the resin material, and is adhered to the resin material,incorporation of air during manufacturing is suppressed, and themovement of the reinforcing cord 26 due to a force applied or the likewhile travelling is suppressed. Thereby, the separation or the like ofthe reinforcing cord 26, the tire case 17 and a tread 30 is suppressed,and the durability of the tire 10 is improved.

In addition, since the depth L of embedding of the reinforcing cord 26is equal to or greater than ⅕ of the diameter D as illustrated in FIG.2, incorporation of air during manufacturing is effectively suppressed,and the movement of the reinforcing cord 26 due to input power or thelike while travelling is further suppressed.

In addition, since the tread 30 that comes into contact with roadsurfaces is constituted of a rubber material that is moreabrasion-resistant than the resin material, the abrasion resistance ofthe tire 10 is improved.

Furthermore, since a annular bead core 18 made of a metallic material isembedded in the bead portion 12, similarly to a pneumatic rubber tire ofthe related art, the tire case 17, that is, the tire 10 is strongly heldto the rim 20.

In addition, furthermore, since a sealing layer 24 formed of a rubbermaterial having higher sealing properties than the resin material isprovided in a portion that comes into contact with the rim 20 of thebead portion 12, the sealing properties between the tire 10 and the rim20 is improved. Therefore, compared to when the tire is sealed with therim 20 using the resin material, the air leakage in the tire is furthersuppressed. In addition, rim fitting properties also are improved whenthe sealing layer 24 is provided.

The above embodiment employs a configuration in which the reinforcingcord 26 is heated, and the resin material in the portion with which theheated reinforcing cord 26 comes into contact is melted or softened, butthe invention according to the ninth aspect is not limited to thisconfiguration, and the reinforcing cord 26 may be embedded in the crownportion 16 after heating the outer circumferential surface of the crownportion 16, in which the reinforcing cord 26 is to be embedded, using ahot air generating apparatus without heating the reinforcing cord 26.

In addition, in Embodiment 9-1, a heater and a fan are used as the heatsource of a cord-heating device 59, but the ninth aspect of theinvention is not limited to this configuration, and a configuration inwhich the reinforcing cord 26 is directly heated using radiation heat(for example, ultraviolet rays or the like) may be employed. Inaddition, the reinforcing cord-embedded portion may be melted orsoftened by making the heat source of the hot air generating apparatus,for example, infrared rays converge at the portion at which thereinforcing cord 26 is embedded.

Furthermore, Embodiment 9-1 employs a configuration in which theportion, in which the thermoplastic resin material having thereinforcing cord 26 embedded therein is melted or softened, is forciblycooled using the second metal roller 64, but the ninth aspect of theinvention is not limited to this configuration, and a configuration inwhich the portion, in which the thermoplastic resin material is meltedor softened, is forcibly cooled and solidified by directly blowing coldair to the portion in which the thermoplastic resin material is meltedor softened.

In addition, Embodiment 9-1 employs a configuration in which thereinforcing cord 26 is heated; however, for example, a configuration inwhich the outer circumference of the reinforcing cord 26 is coated withthe same thermoplastic resin material as the tire case 17 may beemployed, and, in this case, it is possible to effectively suppressincorporation of air during embedding in the crown portion 16 by heatingthe thermoplastic resin material, which is coated with the reinforcingcord 26, when winding the coated reinforcing cord around the crownportion 16 of the tire case 17.

The tire 10 of Embodiment 9-1 is a so-called tubeless tire in which anair chamber is formed between the tire 10 and the rim 20 by mounting thebead portion 12 in the rim 20, but the ninth aspect of the invention isnot limited to this configuration, and the tire may have a complete tubeshape.

The tire having the complete tube shape may be an embodiment in which,for example, three circular-shaped tire frames are disposed in the tirewidth direction as illustrated in FIG. 4. FIG. 4 is a cross-sectionalview of the tire according to other embodiment. As illustrated in FIG.4, the tire 86 has the tread rubber layer 87, circular-shaped hollowtubes (tire frame) 88 which are formed of the same resin material as inEmbodiment 9-1, the belt (reinforcing cord) 89 and the rim 90. Threetubes 88 are disposed in series in the tire width direction of the tire86. The tread rubber layer 87, in which the belt 89 is embedded, isadhered to the outer circumferential portions of the tubes 88. Inaddition, the tubes 88 are mounted on the rim 90 having recess portionsthat engage with the tubes 88. Meanwhile, the bead core is not providedin the tire 86.

In addition, the spiral winding of the reinforcing cord 26 facilitatesthe manufacturing, but a method, in which the reinforcing cord 26 isdiscontinuously formed in the width direction, or the like can be alsoconsidered.

Thus far, an embodiment according to the ninth aspect of the inventionhas been described using the embodiment, but the embodiment is simply anexample, and the invention can be carried out with a variety ofmodifications within the scope of the purport. In addition, it isneedless to say that the scope of right of the invention according tothe ninth aspect is not limited to the above embodiment.

Embodiment 9-2

Next, a method of manufacturing the tire according to the ninth aspectof the invention and Embodiment 9-2 of the tire will be describedaccording to the drawings. Similarly to the above Embodiment 9-1, thetire of the present embodiment exhibits almost the same cross-sectionalshape as an ordinary pneumatic rubber tire of the related art.

Here, the tire according to Embodiment 9-2 is the same as the aboveEmbodiment 1-2 except for the following facts. Therefore, the samereference signs and drawings will be used in the description regardingthe same drawings and members.

In the tire of Embodiment 9-2, similarly to the above Embodiment 9-1,the tire case 17 is formed of a mixed material of a polyamide-basedthermoplastic elastomer (UBESTA, XPA9048 manufactured by Ube Industries,Ltd.), an acid-modified polyolefin (ADOMER QF551 manufactured by MitsuiChemicals, Inc., a glass transition temperature −13° C.) and anolefin-based thermoplastic elastomer including polypropylene (PRIME TPOF-3740 manufactured by Prime Polymer Co., Ltd.) (hereinafter referred tosimply as “resin material” in the description of Embodiment 9-2). Otherportions are the same as in the tire according to the above Embodiment1-2, and the manufacturing method is the same as well.

(Effects)

In the tire 200 of the embodiment, since the tire case 17 is formed ofthe resin material further including the above second thermoplasticelastomer resin in addition to the first thermoplastic elastomer and thespecific resin according to the ninth aspect of the invention, elasticmodulus of the tire case 17 can be controlled, and an increase in therolling resistance of the tire can be suppressed.

In the method of manufacturing the tire of the embodiment, when the tirecase 17, a cushion rubber 29 and a tread rubber 30A are integrated,since the outer circumferential surface 17S of the tire case 17 has beentreated to be coarse, the bonding properties (adhesion) is improved dueto an anchor effect. In addition, since the resin material that formsthe tire case 17 is dug out by the collision of a blasting abrasive,wettability of a bond is improved. Thereby, a state in which the bond isuniformly coated on the outer circumferential surface 17S of the tirecase 17 is held, and the bonding strength between the tire case 17 andthe cushion rubber 29 can be ensured.

Particularly, even when protrusions and recesses are formed on the outercircumferential surface 17S of the tire case 17, the peripheries of therecess portions (recess walls and recess bottoms) are treated to becoarse by making the blasting abrasive collide with the recess portions(voids 28A), and the bonding strength between the tire case 17 and thecushion rubber 29 can be ensured.

Meanwhile, since the cushion rubber 29 is laminated in thecoarsening-treated areas on the outer circumferential surface 17S of thetire case 17, the bonding strength between the tire case 17 and thecushion rubber 29 can be effectively ensured.

When the cushion rubber 29 has been vulcanized in the vulcanizing step,the cushion rubber 29 flows into the coarsened recessed and protrusionsformed on the outer circumferential surface 17S of the tire case 17through the coarsening treatment. In addition, when vulcanization iscompleted, anchor effect is developed due to the cushion rubber 29 thathas flowed into the coarsened recesses and protrusions so that thebonding strength between the tire case 17 and the cushion rubber 29 isimproved.

The tire 200 manufactured using the above method of manufacturing a tireensures the bonding strength between the tire case 17 and the cushionrubber 29, that is, ensures the bonding strength between the tire case17 and the tread 30 through the cushion rubber 29. Thereby, theseparation between the outer circumferential surface 17S of the tirecase 17 of the tire 200 and the cushion rubber 29 at travelling and thelike is suppressed.

In addition, since the outer circumferential portion of the tire case 17is provided with the reinforcing cord layer 28, the puncture resistanceand the cutting resistance are improved compared to a tire case havingthe outer circumferential portion constituted of something other thanthe reinforcing cord layer 28.

In addition, since the reinforcing cord layer 28 is formed by windingthe coated cord member 26B, the stiffness of the tire 200 in thecircumferential direction is improved. The improvement of the stiffnessin the circumferential direction suppresses creeping (a phenomenon inwhich the plastic deformation of the tire case 17 increases over timeunder a constant stress) in the tire case 17, and the pressureresistance with respect to the air pressure from the inside in the tirediameter direction is improved.

In the embodiment, the recesses and protrusions are formed on the outercircumferential surface 17S of the tire case 17, but the ninth aspect ofthe invention is not limited thereto, and a configuration in which theouter circumferential surface 17S is formed to be flat may be employed.

In addition, in the tire case 17, the reinforcing cord layer may beformed by covering the coated cord member, which is wound around andbonded to the crown portion of the tire case, with a thermoplasticmaterial for coating. In this case, a coated layer can be formed bydischarging a thermoplastic material for coating in a molten or softenedstate on the reinforcing cord layer 28. In addition, the coated layermay be formed by heating an adhesive sheet into a molten or softenedstate without using an extruder, and attaching the adhesive sheet to thesurface (outer circumferential surface) of the reinforcing cord layer28.

The above Embodiment 9-2 employs a configuration in which partitionedcase bodies (tire case half parts 17A) are bonded so as to form the tirecase 17, but the invention according to the ninth aspect is not limitedthereto, and the tire case 17 may be integrally formed using a mold orthe like.

The tire 200 of Embodiment 9-2 is a so-called tubeless tire in which anair chamber is formed between the tire 200 and the rim 20 by mountingthe bead portion 12 in the rim 20, but the ninth aspect of the inventionis not limited to this configuration, and the tire 200 may have, forexample, a complete tube shape.

In Embodiment 9-2, the cushion rubber 29 is disposed between the tirecase 17 and the tread 30, but the ninth aspect of the invention is notlimited thereto, and a configuration in which the cushion rubber 29 isnot disposed may be employed.

In addition, Embodiment 9-2 employs a configuration in which the coatedcord member 26B is wound around the crown portion 16 in a spiral shape,but the invention according to the ninth aspect is not limited thereto,and a configuration in which the coated cord member 26B isdiscontinuously formed in the width direction may be employed.

Embodiment 9-2 employs a configuration in which a resin material forcoating 27 that forms a coated cord rubber 26B is used as athermoplastic material, and the resin material for coating 27 is heatedinto a molten or softened state so as to weld the coated cord member 26Bon the outer circumferential surface of the crown portion 16, but theninth aspect of the invention is not limited to this configuration, anda configuration in which the coated cord member 26B is welded on theouter circumferential surface of the crown portion 16 using an adhesiveor the like without heating the resin material for coating 27 may beemployed.

In addition, a configuration in which the resin material for coating 27that forms the coated cord member 26B is used as a thermosetting resinand the coated cord member 26B is welded on the outer circumferentialsurface of the crown portion 16 using an adhesive or the like withoutheating may be employed.

Furthermore, a configuration in which the resin material for coating 27that forms the coated cord member 26B is used as a thermosetting resin,and the tire case 17 is formed of a thermoplastic resin material may beemployed. In this case, the coated cord member 26B may be adhered to theouter circumferential surface of the crown portion 16 using an adhesiveor the like, or the coated cord member 26B may be welded on the outercircumferential surface of the crown portion 16 by heating into a moltenor softened state the portion at which the coated cord member 26B of thetire case 17 is provided.

In addition, furthermore, a configuration in which the resin materialfor coating 27 that forms the coated cord rubber 26B is used as athermoplastic material and the tire case 17 is formed of a thermoplasticresin material. In this case, the coated cord member 26B may be adheredto the outer circumferential surface of the crown portion 16 using anadhesive or the like, or the coated cord member 26B may be welded on theouter circumferential surface of the crown portion 16 by heating theresin material for coating 27 into a molten or softened state, whileheating into a molten or softened state the portion at which the coatedcord member 26B of the tire case 17 is provided. Meanwhile, when boththe tire case 17 and the coated cord member 26B have been heated into amolten or softened state, since both are well mixed, the bondingstrength is improved. In addition, when thermoplastic resin materialsare used as both the resin material that forms the tire case 17 and theresin material for coating 27 that forms the coated cord member 26B, thethermoplastic resin materials are preferably the same kind ofthermoplastic materials, particularly, the same thermoplastic material.

In addition, furthermore, an adhesive may be coated on the outercircumferential surface 17S of the tire case 17, on which the coarseningtreatment has been carried out, after the surface of the outercircumferential surface 17S is activated using a corona treatment, aplasma treatment or the like so as to increase the hydrophilicity.

In addition, furthermore, the order for manufacturing the tire 200 isnot limited to the order in Embodiment 9-1, and may be appropriatelychanged.

Thus far, an embodiment according to the ninth aspect of the inventionhas been described using the embodiment, but the embodiment is simply anexample, and the invention can be carried out with a variety ofmodifications within the scope of the purport. In addition, it isneedless to say that the scope of right of the invention according tothe ninth aspect is not limited to the above embodiment.

Thus far, the specific aspects of the invention according to the ninthaspect have been described using Embodiment 9-1 and Embodiment 9-2, butthe invention according to the ninth aspect is not limited to the aboveaspects.

<<The Tenth Aspect of the Invention>>

Next, a thermoplastic resin material including a polyamide-basedthermoplastic elastomer and a polyester thermoplastic elastomer, whichconstitutes the tire frame in the tenth aspect of the invention, and aresin material as a component of the reinforcing cord layer will bedescribed, and, subsequently, a specific embodiment of the tire of thetenth aspect of the invention will be described using the drawings.

[Thermoplastic Resin]

A tire of the tenth aspect of the invention includes at least a circulartire frame formed of a thermoplastic resin material including apolyamide-based thermoplastic elastomer and a polyester-basedthermoplastic elastomer.

Here, the “polyamide-based thermoplastic elastomer” refers to athermoplastic resin material which is made of a copolymer including apolymer that constitutes a crystalline hard segment having a highmelting point, and a polymer that constitutes a non-crystalline softsegment having a low glass transition temperature, and which has anamide bond (—CONH—) in the main chain of the polymer that constitutesthe hard segment. As the “polyamide-based thermoplastic elastomer” inthe present embodiment, the same polyamide-based thermoplastic elastomeras in the above first aspect of the invention can be used.

—Polyester-Based Thermoplastic Elastomer—

The “polyester-based thermoplastic elastomer” is an elasticmacromolecular compound, and refers to a thermoplastic resin materialmade of a copolymer including a polymer that constitutes a crystallinehard segment having a high melting point, and a polymer that constitutesa non-crystalline soft segment having a low glass transitiontemperature, in which a polyester resin is included as the polymer thatconstitutes the hard segment. The “polyester-based thermoplasticelastomer” in the present embodiment is the same as in the above secondaspect of the invention.

A commercially available product can be used as the polyester-basedthermoplastic elastomer, and examples thereof include “HYTREL” seriesmanufactured by Du Pont-Toray Co., Ltd. (for example, 3046, 5557, 6347,4047, 4767), “PELPRENE series manufactured by Toyobo Co., Ltd. (forexample, P30B, P40B, P40H. P55B, P70B, P150B, P250B, E450B, P150M,S1001, S2001, S5001, S6001, S9001 and the like), and the like.

The mass ratio (x:y) between the polyamide-based thermoplastic elastomer(x) and the polyester-based thermoplastic elastomer (y) in thethermoplastic resin is preferably from 95:5 to 50:50. When the massratio between these elastomers is from 95:5 to 50:50, thepolyamide-based thermoplastic elastomer and the polyester-basedthermoplastic elastomer can have the characteristics of thepolyester-based thermoplastic elastomer while maintaining thecharacteristics of the polyamide-based thermoplastic elastomer so thatthe elastic modulus of the tire can be easily controlled whilemaintaining the weldability between the reinforcing cord member and thetire frame through the polyamide-based thermoplastic elastomer, wherebythe durability of the tire is further improved, and it is possible tomake a tire that is more unlikely to be deformed due to a change intemperature. The mass ratio (x:y) between the polyamide-basedthermoplastic elastomer (x) and the polyester-based thermoplasticelastomer (y) is more preferably from 90:10 to 50:50.

In addition, the total content of the polyamide-based thermoplasticelastomer and the polyester-based thermoplastic elastomer in thethermoplastic resin material is not particularly limited, but ispreferably 50 mass % to 100 mass % with respect to the total mass of thethermoplastic resin material. When the total content is 50 mass % ormore with respect to the total mass of the thermoplastic resin material,it is possible to sufficiently develop the characteristics of thethermoplastic resin material, and it is possible to improve the heatresistance, durability and productivity of the tire.

The thermoplastic resin material may contain rubbers, thermoplasticelastomers other than the polyamide-based thermoplastic elastomer andthe polyester-based thermoplastic elastomer, thermoplastic resins, avariety of fillers (for example, silica, calcium carbonate and clay) anda variety of additives, such as an age inhibitor, oil, a plasticizer, acoloring agent, a weather-resisting agent and a reinforcing material, asdesired.

The thermoplastic resin material can be obtained by mixing thepolyamide-based thermoplastic elastomer and the polyester-basedthermoplastic elastomer, adding a variety of additives as necessary, andmelting and mixing the components. The mixing ratio between thepolyamide-based thermoplastic elastomer and the polyester-basedthermoplastic elastomer is based on the ratio described above. The resinobtained through melting and mixing can be used in a pellet shape asnecessary.

The tensile modulus of elasticity, which is defined in JIS K7113:1995,of the thermoplastic resin material according to the tenth aspect of theinvention is preferably 100 MPa to 1000 MPa, more preferably 100 MPa to800 MPa, and particularly preferably 100 MPa to 700 MPa. When thetensile modulus of elasticity of the resin material is 100 MPa to 1000MPa, fitting onto a rim can be efficiently carried out while holding theshape of the tire frame.

The tensile yield strength, which is defined in JIS K7113:1995, of thethermoplastic resin material according to the tenth aspect of theinvention is preferably 5 MPa or more, preferably 5 MPa to 20 MPa, andstill more preferably 5 MPa to 17 MPa. When the tensile yield strengthof the thermoplastic resin material is 5 MPa or more, it is possible towithstand deformation caused by a load applied to the tire at the timeof driving or the like.

The tensile yield elongation, which is defined in JIS K7113:1995, of thethermoplastic resin material according to the tenth aspect of theinvention is preferably 10% or more, preferably 10% to 70%, and stillmore preferably 15% to 60%. When the tensile yield elongation of thethermoplastic resin material is 10% or more, it is possible to increasethe elastic region and improve the fittability onto a rim.

The tensile elongation at break, which is defined in JIS K7113:1995, ofthe thermoplastic resin material according to the tenth aspect of theinvention is preferably 50% or more, preferably 100% or more, still morepreferably 150% or more, and particularly preferably 200% or more. Whenthe tensile elongation at break of the resin material is 50% or more, itis possible to improve the fittability onto a rim and avoid fracture dueto collision.

The deflection temperature under load (under a load of 0.45 MPa), whichis defined in ISO75-2 or ASTM D648, of the thermoplastic resin materialaccording to the tenth aspect of the invention is preferably 50° C. ormore, preferably 50° C. to 150° C., and still more preferably 50° C. to130° C. When the deflection temperature under load of the thermoplasticresin material is 50° C. or more, it is possible to suppress deformationof a tire frame even when vulcanization is carried out in the productionof a tire.

[The Resin Material as a Component of the Reinforcing Cord Layer]

The tire of the tenth aspect of the invention may have a reinforcingcord member which is wound around the outer circumference of the tireframe in the circumferential direction so as to form a reinforcing cordlayer.

The “resin material as a component of the reinforcing cord layer”according to the tenth aspect of the invention is the same as the “resinmaterial as a component of the reinforcing cord layer” according to thefirst aspect of the invention.

Embodiment 10-1

Hereinafter, a tire according to Embodiment 10-1 of the tire of thetenth aspect of the invention will be described according to thedrawings.

Here, the tire according to Embodiment 10-1 is the same as the aboveEmbodiment 1-1 except for the following points. Therefore, the samereference numerals and drawings will be used in the descriptionregarding the same drawings and members.

The tire case 17 of the present embodiment is formed of a thermoplasticresin material including a polyamide-based thermoplastic elastomer(“UBESTA, XPA9048X1” manufactured by Ube Industries, Ltd.) and apolyester-based thermoplastic elastomer (“HYTREL5557” manufactured by DuPont-Toray Co., Ltd.) at a mass ratio of 75:25. In the presentembodiment, the tire case 17 is formed of the thermoplastic resinmaterial according to the tenth aspect of the invention alone, but thetenth aspect of the invention is not limited to this configuration, and,similarly to an ordinary pneumatic rubber tire of the related art, otherthermoplastic resin materials having different characteristics may beused in the respective portions (the side portions 14, the crown portion16, the bead portions 12, and the like) of the tire case 17. Otherpoints are the same as in the tire according to the above Embodiment1-1, and the manufacturing method is also the same.

(Effects)

In the tire 10 of the present embodiment, since the tire case 17 isformed of the thermoplastic resin material including a polyamide-basedthermoplastic elastomer (“UBESTA, XPA9048X1” manufactured by UbeIndustries, Ltd.) and a polyester-based thermoplastic elastomer(“HYTREL5557” manufactured by Du Pont-Toray Co., Ltd.) at a mass ratioof 75:25, thermal resistance, tensile modulus of elasticity, tensilestrength and fracture strain are excellent, and the temperaturedependency of the tensile yield strength is small. Furthermore, theweight is light compared to rubber of the related art. Therefore, thetire 10 of the present embodiment is excellent in terms of durability,is not easily influenced by a change in temperature, and exhibits lowfuel consumption when used in an automobile.

In addition, the polyamide-based thermoplastic elastomer, which is oneof the components of the thermoplastic resin material, has high adhesionproperties to the reinforcing cord 26, and, furthermore, is excellent interms of fixing performances, such as weld strength. Therefore, it ispossible to suppress the phenomenon in which air remains around thereinforcing cord 26 in the reinforcing cord winding process(incorporation of air). When the adhesion properties and weldability tothe reinforcing cord 26 are high, and, furthermore, incorporation of airinto the periphery of the reinforcing cord member is suppressed, it ispossible to effectively suppress the movement of the reinforcing cord 26caused by a force applied thereto at the time of driving or the like.Thereby, for example, even when a tire-constituting member has beenprovided so as to cover the entirety of the reinforcing cord member onthe outer circumference of the tire frame, since the movement of thereinforcing cord member is suppressed, the separation or the like of themembers (including the tire frame) is suppressed, and the durability ofthe tire 10 is improved.

In addition, in the tire 10 of the present embodiment, since thereinforcing cord 26 having a higher stiffness than the thermoplasticresin material is helically wound in the circumferential direction onthe outer circumferential surface of the crown portion 16 in the tirecase 17 formed of the thermoplastic resin material, the punctureresistance, the cutting resistance and the stiffness of the tire 10 inthe circumferential direction are improved. Meanwhile, the improvementof the stiffness of the tire 10 in the circumferential directionprevents the creeping in the tire case 17 formed of the thermoplasticresin material.

In addition, in the cross-sectional view of the tire case 17 along theaxial direction (the cross section illustrated in FIG. 1), since atleast a portion of the reinforcing cord 26 is embedded in the outercircumferential surface of the crown portion 16 in the tire case 17formed of the thermoplastic resin material, and is adhered to thethermoplastic resin material, incorporation of air during manufacturingis suppressed, and the movement of the reinforcing cord 26 caused by aforce applied thereto at the time of driving or the like is suppressed.Thereby, the separation or the like of the reinforcing cord 26, the tirecase 17 and the tread 30 is suppressed, and the durability of the tire10 is improved.

In addition, since the depth L of embedding of the reinforcing cord 26is ⅕ or more of the diameter D as illustrated in FIG. 2, incorporationof air during manufacturing is effectively suppressed, and the movementof the reinforcing cord 26 caused by a force applied thereto at the timeof driving or the like is further suppressed.

When the reinforcing cord layer 28 is configured to include thethermoplastic resin material as described above, since it is possible todecrease the difference in hardness between the tire case 17 and thereinforcing cord layer 28 compared to the case when the reinforcing cord26 is fixed using cushion rubber, the reinforcing cord 26 can be furtheradhered and fixed to the tire case 17. Thereby, the above incorporationof air can be effectively prevented, and it is possible to effectivelysuppress the movement of the reinforcing cord member at the time ofdriving.

Furthermore, when the reinforcing cord is a steel cord, since thereinforcing cord 26 can be easily separated and collected from thethermoplastic resin material through heating when disposing of the tire,it is advantageous in terms of the recycling properties of the tire 10.In addition, the resin material generally has a low loss factor (Tan δ)compared to vulcanized rubber. Therefore, when the reinforcing cordlayer includes a large amount of the resin material, it is possible toimprove the rolling properties of the tire. Furthermore, the resinmaterial having a relatively high elastic modulus compared to vulcanizedrubber is advantageous in that the in-plane shear stiffness is large,and steering stability and abrasion resistance during driving with thetire are also excellent.

In addition, since the tread 30 that comes into contact with roadsurfaces is made of a rubber material that is more abrasion-resistantthan the thermoplastic resin material, the abrasion resistance of thetire 10 is improved.

Furthermore, since an annular bead core 18 made of a metallic materialis embedded in the bead portion 12, the tire case 17, that is, the tire10 is strongly held to the rim 20 similarly to a pneumatic rubber tireof the related art.

In addition, furthermore, since a sealing layer 24 made of a rubbermaterial having higher sealing properties than the thermoplastic resinmaterial is provided in a portion, which comes into contact with the rim20, of the bead portion 12, the sealing properties between the tire 10and the rim 20 are improved. Therefore, compared to the case whensealing is carried out between the rim 20 and the thermoplastic resinmaterial, the air leakage from the tire is further suppressed. Inaddition, the rim fitting properties are also improved when the sealinglayer 24 is provided.

The above embodiment employs a configuration in which the reinforcingcord 26 is heated, and the thermoplastic resin material in the portionwith which the heated reinforcing cord 26 comes into contact is meltedor softened, but the tenth aspect of the invention is not limited tothis configuration, and the reinforcing cord 26 may be embedded in thecrown portion 16 after heating the outer circumferential surface of thecrown portion 16, in which the reinforcing cord 26 is to be embedded,using a hot air generating apparatus without heating the reinforcingcord 26.

In addition, in Embodiment 10-1, a heater and a fan are used as the heatsource of a cord heating device 59, but the tenth aspect of theinvention is not limited to this configuration, and a configuration inwhich the reinforcing cord 26 is directly heated using radiation heat(for example, infrared rays or the like) may be employed.

Furthermore, Embodiment 10-1 employs a configuration in which theportion, in which the thermoplastic resin material having thereinforcing cord 26 embedded therein is melted or softened, is forciblycooled using the second metal roller 64, but the tenth aspect of theinvention is not limited to this configuration, and a configuration inwhich the portion, in which the thermoplastic resin material is meltedor softened, is forcibly cooled and solidified by directly blowing coldair to the portion in which the thermoplastic resin material is meltedor softened may be employed.

In addition, Embodiment 10-1 employs a configuration in which thereinforcing cord 26 is heated; however, for example, a configuration inwhich the outer circumference of the reinforcing cord 26 is coated withthe same thermoplastic resin material as the tire case 17 may beemployed, and, in this case, it is possible to effectively suppressincorporation of air during embedding in the crown portion 16 by heatingthe reinforcing cord 26 and the coating of the thermoplastic resinmaterial when winding the coated reinforcing cord around the crownportion 16 of the tire case 17.

In addition, the helical winding of the reinforcing cord 26 is easy inthe manufacturing, but a method, in which the reinforcing cord 26 isformed to be discontinuous in the width direction, or the like can bealso considered.

The tire 10 of Embodiment 10-1 is a so-called tubeless tire in which anair chamber is formed between the tire 10 and the rim 20 by mounting thebead portion 12 on the rim 20, but the tenth aspect of the invention isnot limited to this configuration, and the tire may have a complete tubeshape.

Thus far, an embodiment of the tenth aspect of the invention has beendescribed using the embodiment, but the embodiment is simply an example,and the invention can be carried out with a variety of modificationswithin the scope of the purport. In addition, it is needless to say thatthe scope of right of the tenth aspect of the invention is not limitedto the above embodiment.

Embodiment 10-2

Next, the tire and the method of manufacturing the tire of the tenthaspect of the invention according to Embodiment 10-2 will be describedaccording to the drawings. Similarly to the above Embodiment 10-1, thetire of the present embodiment exhibits substantially the samecross-sectional shape as an ordinary pneumatic rubber tire of therelated art.

Here, the tire according to Embodiment 10-2 is the same as the aboveEmbodiment 1-2 except for the following points. Therefore, the samereference numerals and drawings will be used in the descriptionregarding the same drawings and members.

In the tire of Embodiment 10-2, similarly to the above Embodiment 10-1,the tire case 17 is formed of a thermoplastic resin material including apolyamide-based thermoplastic elastomer (“UBESTA XPA9048X1” manufacturedby Ube Industries, Ltd.) and a polyester-based thermoplastic elastomer(“HYTREL5557” manufactured by Du Pont-Toray Co., Ltd.) at a mass ratioof 75:25. Other points are the same as in the tire according to theabove Embodiment 1-2, and the manufacturing method is also the same.

(Effects)

In the tire 200 of present the embodiment, since the tire case 17 isformed of the thermoplastic resin material including a polyamide-basedthermoplastic elastomer and a polyester-based thermoplastic, thermalresistance, tensile modulus of elasticity, tensile strength and fracturestrain are excellent, and the temperature dependency of the tensileyield strength is small. Furthermore, since the tire structure can besimplified, the weight is light compared to rubber of the related art.Therefore, the tire 200 of the present embodiment is excellent in termsof durability, is not easily influenced by a change in temperature, andexhibits low fuel consumption when used in an automobile.

In addition, when the reinforcing cord layer 28 is configured to includethe coated cord member 26B, since it is possible to decrease thedifference in hardness between the tire case 17 and the reinforcing cordlayer 28 compared to the case when the reinforcing cord 26A is simplyfixed using cushion rubber 29, the coated cord member 26B can be furtheradhered and fixed to the tire case 17. Thereby, the above incorporationof air can be effectively prevented, and it is possible to effectivelysuppress the movement of the reinforcing cord member at the time ofdriving.

Furthermore, when the reinforcing cord is a steel cord, since the cordmember 26A can be easily separated and collected from the coated cordmember 26B through heating when disposing of the tire, it isadvantageous in terms of the recycling properties of the tire 200. Inaddition, the resin material generally has a low loss factor (Tan δ)compared to vulcanized rubber. Therefore, when the reinforcing cordlayer includes a large amount of the resin material, it is possible toimprove the rolling properties of the tire. Furthermore, the resinmaterial having a relatively high elastic modulus compared to vulcanizedrubber is advantageous in that the in-plane shear stiffness is large,and steering stability and abrasion resistance during driving with thetire are also excellent.

In the method of manufacturing the tire of the present embodiment, whenthe tire case 17, the cushion rubber 29 and a tread rubber 30A areintegrated, since the outer circumferential surface 17S of the tire case17 has been subjected to a roughening treatment, the bonding properties(adhesion properties) are improved due to the anchor effect. Inaddition, since the resin material that forms the tire case 17 is dug upby the collision of a blasting abrasive, the wettability of a bondingagent is improved. Thereby, a state in which the bonding agent isuniformly coated on the outer circumferential surface 17S of the tirecase 17 is held, and the bonding strength between the tire case 17 andthe cushion rubber 29 can be ensured.

Particularly, even when protrusions and recesses are formed on the outercircumferential surface 17S of the tire case 17, the peripheries of therecess portions (recess walls and recess bottoms) are subjected to aroughening treatment by making the blasting abrasive collide with therecess portions (voids 28A), and the bonding strength between the tirecase 17 and the cushion rubber 29 can be ensured.

Meanwhile, since the cushion rubber 29 is laminated in theroughening-treated areas on the outer circumferential surface 17S of thetire case 17, the bonding strength between the tire case 17 and thecushion rubber can be effectively ensured.

When the cushion rubber 29 has been vulcanized in a vulcanizing process,the cushion rubber 29 flows into the roughened recesses and protrusionsformed on the outer circumferential surface 17S of the tire case 17through the roughening treatment. In addition, when vulcanization iscompleted, the anchor effect is developed due to the cushion rubber 29that has flowed into the roughened recesses and protrusions so that thebonding strength between the tire case 17 and the cushion rubber 29 isimproved.

The tire 200 manufactured using the above method of manufacturing a tireensures the bonding strength between the tire case 17 and the cushionrubber 29, that is, ensures the bonding strength between the tire case17 and the tread 30 through the cushion rubber 29. Thereby, theseparation between the outer circumferential surface 17S of the tirecase 17 of the tire 200 and the cushion rubber 29 is suppressed at thetime of driving or the like.

In addition, since the outer circumference of the tire case 17 is madeof the reinforcing cord layer 28, the puncture resistance and thecutting resistance are improved compared to a case in which the outercircumference is made of something other than the reinforcing cord layer28.

In addition, since the reinforcing cord layer 28 is formed by windingthe coated cord member 26B, the stiffness of the tire 200 in thecircumferential direction is improved. The improvement of the stiffnessin the circumferential direction suppresses creeping (a phenomenon inwhich the plastic deformation of the tire case 17 increases over timeunder a constant stress) in the tire case 17, and the pressureresistance with respect to the air pressure from the inside in the tireradial direction is improved.

In the present embodiment, the recesses and protrusions are formed onthe outer circumferential surface 17S of the tire case 17, but the tenthaspect of the invention is not limited thereto, and a configuration inwhich the outer circumferential surface 17S is formed to be flat may beemployed.

In addition, in the tire case 17, the reinforcing cord layer may beformed by covering the coated cord member, which is wound around andbonded to the crown portion of the tire case, with a thermoplasticmaterial for coating. In this case, a coating layer can be formed bydischarging a thermoplastic material for coating in a molten or softenedstate on the reinforcing cord layer 28. In addition, the coating layermay be formed by heating a welding sheet into a molten or softened statewithout using an extruder, and attaching the welding sheet to thesurface (outer circumferential surface) of the reinforcing cord layer28.

The above Embodiment 10-2 employs a configuration in which case dividedparts (tire case half parts 17A) are bonded so as to form the tire case17, but the tenth aspect of the invention is not limited thereto, andthe tire case 17 may be integrally formed using a mold or the like.

The tire 200 of Embodiment 10-2 is a so-called tubeless tire in which anair chamber is formed between the tire 200 and the rim 20 by mountingthe bead portion 12 on the rim 20, but the tenth aspect of the inventionis not limited to this configuration, and the tire 200 may have, forexample, a complete tube shape.

In Embodiment 10-2, the cushion rubber 29 is disposed between the tirecase 17 and the tread 30, but the tenth aspect of the invention is notlimited thereto, and a configuration in which the cushion rubber 29 isnot disposed may be employed.

In addition, Embodiment 10-2 employs a configuration in which the coatedcord member 26B is helically wound around the crown portion 16, but thetenth aspect of the invention is not limited thereto, and aconfiguration in which the coated cord member 26B is wound to bediscontinuous in the width direction may be employed.

Embodiment 10-2 employs a configuration in which a thermoplasticmaterial is used as the resin material for coating 27 that forms thecoated cord member 26B, and the resin material for coating 27 is heatedinto a molten or softened state so as to weld the coated cord member 26Bon the outer circumferential surface of the crown portion 16, but thetenth aspect of the invention is not limited to this configuration, anda configuration in which the coated cord member 26B is adhered to theouter circumferential surface of the crown portion 16 using an adhesiveor the like without heating the resin material for coating 27 may beemployed.

In addition, a configuration in which a thermosetting resin is used asthe resin material for coating 27 that forms the coated cord member 26B,and the coated cord member 26B is adhered to the outer circumferentialsurface of the crown portion 16 using an adhesive or the like withoutheating may be employed.

Furthermore, a configuration in which a thermosetting resin is used asthe resin material for coating 27 that forms the coated cord member 26B,and the tire case 17 is formed of a thermoplastic resin material may beemployed. In this case, the coated cord member 26B may be adhered to theouter circumferential surface of the crown portion 16 using an adhesiveor the like, or the coated cord member 26B may be welded on the outercircumferential surface of the crown portion 16 by heating the portion,which is to be provided with the coated cord member 26B, of the tirecase 17 into a molten or softened state.

In addition, furthermore, a configuration in which a thermoplasticmaterial is used as the resin material for coating 27 that forms thecoated cord member 26B, and the tire case 17 is formed of athermoplastic resin material may be employed. In this case, the coatedcord member 26B may be adhered to the outer circumferential surface ofthe crown portion 16 using an adhesive or the like, or the coated cordmember 26B may be welded on the outer circumferential surface of thecrown portion 16 by heating the portion, which is to be provided withthe coated cord member 26B, of the tire case 17 into a molten orsoftened state, and heating the resin material for coating 27 into amolten or softened state. Meanwhile, when both the tire case 17 and thecoated cord member 26B have been hated into a molten or softened state,since both are well mixed, the bonding strength is improved. Inaddition, when thermoplastic resin materials are used as both the resinmaterial that forms the tire case 17 and the resin material for coating27 that forms the coated cord member 26B, the thermoplastic resinmaterials are preferably the same kind of thermoplastic materials,particularly, the same thermoplastic material.

In addition, furthermore, an adhesive may be coated on the outercircumferential surface 17S of the tire case 17, after the surface ofthe outer circumferential surface 17S, on which the roughening treatmenthas been carried out, is activated using a corona treatment, a plasmatreatment or the like so as to increase the hydrophilicity.

In addition, furthermore, the order for manufacturing the tire 200 isnot limited to the order in Embodiment 10-2, and may be appropriatelychanged.

Thus far, an embodiment of the tenth aspect of the invention has beendescribed using the embodiment, but the embodiment is simply an example,and the invention can be carried out with a variety of modificationswithin the scope of the purport. In addition, it is needless to say thatthe scope of right of the tenth aspect of the invention is not limitedto the above embodiment.

Thus far, the specific embodiments of the tenth aspect of the inventionhave been described using Embodiment 10-1 and Embodiment 10-2, but thetenth aspect of the invention is not limited to the above embodiments.

<<The Eleventh Aspect of the Invention>>

Next, a thermoplastic resin material that constitutes the tire frame inthe eleventh aspect of the invention will be described, and,subsequently, a specific embodiment of the tire of the eleventh aspectof the invention will be described using the drawings.

[Thermoplastic Resin Material]

The tire of the eleventh aspect of the invention is a tire including atleast a circular tire frame formed of a thermoplastic resin material, inwhich the thermoplastic resin material contains a polyamide-basedthermoplastic elastomer and at least one copolymer selected from anolefin-(meth)acrylate copolymer or a metal crosslinked product of anolefin-(meth)acrylic acid copolymer.

Since a polyamide-based thermoplastic elastomer and a specific copolymerare contained in the thermoplastic resin material according to theeleventh aspect of the invention, a tire can be obtained in which theimpact resistance is excellent, and the temperature dependency oftensile yield strength is suppressed, when the thermoplastic resinmaterial according to the eleventh aspect of the invention is applied tothe tire.

Hereinafter, the thermoplastic elastomer and the specific copolymer willbe described.

[Polyamide-Based Thermoplastic Elastomer]

The “polyamide-based thermoplastic elastomer” is an elasticmacromolecular compound, and refers to a thermoplastic resin materialwhich is made of a copolymer including a polymer that constitutes acrystalline hard segment having a high melting point, and a polymer thatconstitutes a non-crystalline soft segment having a low glass transitiontemperature, and which has an amide bond (—CONH—) in the main chain ofthe polymer that constitutes the hard segment.

Examples of crystalline polyamide that constitutes the hard segmentinclude aliphatic polyamides, such as polycaproamide (nylon-6),poly-ω-aminoheptanoic acid (nylon-7), poly-ω-aminononanoic acid(nylon-9), polyundecaneamide (nylon-11), polylauryl lactam (nylon-12),polyethylene diamine adipamide (nylon-2,6), polytetramethylene adipamide(nylon-4,6), polyhexamethylene adipamide (nylon-6,6), polyhexamethylenesebacamide (nylon-6,10), polyhexamethylene dodecamide (nylon-6,12),polyoctamethylene adipamide (nylon-8,6) and polydecamethylene adipamide(nylon-10,8); crystalline aromatic polyamides obtained through apolycondensation reaction between an aromatic diamine, such asmeta-xylene diamine or para-xylene diamine, and a dicarboxylic acid,such as adipic acid, suberic acid, sebacic acid, cyclohexanedicarboxylic acid, terephthalic acid or isophthalic acid, or aderivative thereof; and the like.

Among the above, nylon-6, nylon-6,6, nylon-12 and the like arepreferable, and nylon-12 is more preferable. As the “polyamide-basedthermoplastic elastomer” in the present embodiment, the samepolyamide-based thermoplastic elastomer as in the above first aspect ofthe invention can be used.

[Specific Copolymer]

The thermoplastic resin material according to the eleventh aspect of theinvention contains the specific copolymer, that is, at least onecopolymer selected from an olefin-(meth)acrylate copolymer or a metalcrosslinked product of an olefin-(meth)acrylic acid copolymer.

—Olefin-(Meth)Acrylate Copolymer—

The olefin-(meth)acrylate copolymer refers to a copolymer including apartial structure derived from (meth)acrylate in the repeating unit ofan olefin, and may be a radical polymer, a block copolymer or a graftcopolymer.

(Meth)acrylate specifically refers to an alkyl ester of (meth)acrylicacid, and examples of an alkyl group that can form an alkyl esterinclude a dodecyl group, an octyl group, a hexyl group, a butyl group, apropyl group, an ethyl group, a methyl group and the like, each of whichis linear, branched, or cyclic. Among the above, from the viewpoint ofproviding hardness to the thermoplastic resin material and improving thedeformation resistance, a butyl group or an ethyl group is preferable,and a butyl group is more preferable.

In addition, in the olefin-(meth)acrylate copolymer, the olefin thatconstitutes the repeating unit of the olefin is preferably ethylene,propylene or 1-butene, and is more preferably ethylene.

That is, the olefin-(meth)acrylate copolymer is preferably anethylene-(meth)acrylate copolymer, more preferably anethylene-(meth)acrylate ethyl ester copolymer or anethylene-(meth)acrylate butyl ester copolymer, and still more preferablyan ethylene-acrylate butyl ester copolymer.

The olefin-(meth)acrylate copolymer may be used solely, or may be usedin combination of two or more kinds.

Metal Crosslinked Product of an Olefin-(Meth)Acrylic Acid Copolymer

The metal crosslinked product of an olefin-(meth)acrylic acid copolymeris a copolymer including a partial structure derived from (meth)acrylicacid in the repeating unit of an olefin, in which —COO⁻s obtained byremoving the proton (H⁺) from (meth)acrylic acid in the repeating unitof (meth)acrylic acid are bonded (crosslinked) to each other throughmetal ions (M^(n+); M represents metal, and n represents the valence ofthe metal). Such a metal crosslinked product of a copolymer is alsocalled an ionomer. The form of the copolymer may be a radical copolymer,a block copolymer or a graft copolymer.

Examples of a metal ion that can form a crosslinking structure with COO⁻in (meth)acrylate include monovalent ions, such as lithium (Li⁺), sodium(Na⁺) and potassium (K⁺); divalent ions, such as magnesium (Mg⁺),calcium (Ca²⁺), barium (Ba²⁺) and zinc (Zn²⁺); trivalent ions, such asaluminum (Al³⁺); and the like. Generally, a metal ion, such as lithium(Li⁺), sodium (Na⁺), magnesium (Mg²⁺) or zinc (Zn²⁺), is used; however,among the above, a zinc ion is preferable from the viewpoint ofproviding hardness to the thermoplastic resin material and improvingdeformation resistance.

In addition, in the metal crosslinked product of theolefin-(meth)acrylic acid copolymer, the olefin that constitutes therepeating unit of the olefin is preferably ethylene, propylene or1-butene, and is more preferably ethylene.

That is, the metal crosslinked product of the olefin-(meth)acrylic acidcopolymer is preferably a metal crosslinked product of anethylene-(meth)acrylic acid copolymer, more preferably a metalcrosslinked product of an ethylene-(meth)acrylic acid copolymer, andstill more preferably a zinc ion-crosslinked product of anethylene-methacrylic acid copolymer.

The metal crosslinked product of the olefin-(meth)acrylic acid copolymermay be used solely, or may be used in combination of two or more kinds.

In addition, as described above, as the specific copolymer, at least oneof an olefin-(meth)acrylate copolymer or a metal crosslinked product ofan olefin-(meth)acrylic acid copolymer may be used. When anolefin-(meth)acrylate copolymer and a metal crosslinked product of anolefin-(meth)acrylic acid copolymer are both used, one kind of amaterial may be used for each of an olefin-(meth)acrylate copolymer anda metal crosslinked product of an olefin-(meth)acrylic acid copolymer,or two or more kinds of materials may be used for either or both of theolefin-(meth)acrylate copolymer and the metal crosslinked product of anolefin-(meth)acrylic acid copolymer.

The number average molecular weight of the specific copolymer ispreferably 5,000 to 10,000,000, and more preferably 7,000 to 1,000,000for both the olefin-(meth)acrylate copolymer and the metal crosslinkedproduct of the olefin-(meth)acrylic acid copolymer from the viewpoint ofthe melt moldability of the thermoplastic resin material.

The mass ratio (x:y) between the polyamide-based thermoplastic elastomer(x) and the specific copolymer (y) in the thermoplastic resin materialis preferably from 95:5 to 50:50, and more preferably from 90:10 to50:50 from the viewpoint of impact resistance.

In addition, in the thermoplastic resin material, the total content ofthe polyamide-based thermoplastic elastomer and the specific copolymerin the thermoplastic resin material is preferably 50 mass % to 100 mass%, and more preferably 50 mass % to 90 mass % with respect to the totalmass of the thermoplastic resin material from the viewpoint ofsufficiently developing the performances of the thermoplastic resinmaterial.

The thermoplastic resin material may contain a variety of fillers (forexample, silica, calcium carbonate and clay) and a variety of additives,such as an age inhibitor, oil, a plasticizer, a coloring agent, aweather-resisting agent and a reinforcing material, as desired.

The thermoplastic resin material can be obtained by mixing thepolyamide-based thermoplastic elastomer and the specific copolymer,adding a variety of additives as necessary, and melting and mixing thecomponents. The mixing ratio between the polyamide-based thermoplasticelastomer and the specific copolymer is based on the ratio describedabove. The thermoplastic resin material obtained through melting andmixing can be used in a pellet shape as necessary.

The tensile modulus of elasticity (in the specification, the “elasticmodulus” refers to the tensile modulus of elasticity unless particularlyotherwise described), which is defined in JIS K7113:1995, of thethermoplastic resin material according to the eleventh aspect of theinvention is preferably 100 MPa to 1000 MPa, more preferably 100 MPa to800 MPa, and particularly preferably 100 MPa to 700 MPa. When thetensile modulus of elasticity of the thermoplastic resin material is 100MPa to 1000 MPa, fitting onto a rim can be efficiently carried out whileholding the shape of the tire frame.

The tensile yield strength, which is defined in JIS K7113:1995, of thethermoplastic resin material according to the eleventh aspect of theinvention is preferably 5 MPa or more, preferably 5 MPa to 20 MPa, andstill more preferably 5 MPa to 17 MPa. When the tensile yield strengthof the thermoplastic resin material is 5 MPa or more, it is possible towithstand deformation caused by a load applied to the tire at the timeof driving or the like.

The tensile yield elongation, which is defined in JIS K7113:1995, of thethermoplastic resin material according to the eleventh aspect of theinvention is preferably 10% or more, preferably 10% to 70%, and stillmore preferably 15% to 60%. When the tensile yield elongation of thethermoplastic resin material is 10% or more, it is possible to increasethe elastic region and improve the fittability onto a rim.

The tensile elongation at break, which is defined in JIS K7113:1995, ofthe thermoplastic resin material according to the eleventh aspect of theinvention is preferably 50% or more, preferably 100% or more, still morepreferably 150% or more, and particularly preferably 200% or more. Whenthe tensile elongation at break of the resin material is 50% or more, itis possible to improve the fittability onto a rim and avoid fracture dueto collision.

The deflection temperature under load (under a load of 0.45 MPa), whichis defined in ISO75-2 or ASTM D648, of the thermoplastic resin materialaccording to the eleventh aspect of the invention is preferably 50° C.or more, preferably 50° C. to 150° C., and still more preferably 50° C.to 130° C. When the deflection temperature under load of thethermoplastic resin material is 50° C. or more, it is possible tosuppress deformation in a vulcanization process of a tread or the like.

[The Resin Material as a Component of the Reinforcing Cord Layer]

The tire of the eleventh aspect of the invention may have thereinforcing cord member which is wound around the outer circumference ofthe tire frame in the circumferential direction so as to form thereinforcing cord layer.

The “resin material as a component of the reinforcing cord layer”according to the eleventh aspect of the invention is the same as the[resin material as a component of the reinforcing cord layer] accordingto the first aspect of the invention.

Embodiment 11-1

Hereinafter, a tire according to Embodiment 11-1 of the tire of theeleventh aspect of the invention will be described according to thedrawings.

Here, the tire according to Embodiment 11-1 is the same as the aboveEmbodiment 1-1 except for the following points. Therefore, the samereference numerals and drawings will be used in the descriptionregarding the same drawings and members.

The tire case 17 of the present embodiment is formed of a thermoplasticresin material made of a mixed material of a polyamide-basedthermoplastic elastomer (“UBESTA, XPA9055X1” manufactured by UbeIndustries, Ltd.) and a Zn ionomer of an ethylene-methacrylic acidcopolymer (“HIMILAN, 1855Zn” manufactured by Du Pont-MitsuiPolychemicals Co., Ltd.). In the present embodiment, the tire case 17 isformed of the thermoplastic resin material according to the eleventhaspect of the invention alone, but the eleventh aspect of the inventionis not limited to this configuration, and, similarly to an ordinarypneumatic rubber tire of the related art, other thermoplastic resinmaterials having different characteristics may be used in the respectiveportions (the side portions 14, the crown portion 16, the bead portions12, and the like) of the tire case 17. Other points are the same as inthe tire according to the above Embodiment 1-1, and the manufacturingmethod is also the same.

The tire case 17 of the present embodiment is a pair of the mutuallybonded tire case half parts (tire frame pieces) 17A that are formed ofthe thermoplastic resin material according to the eleventh aspect of theinvention. The tire case is formed by making the circular tire case halfparts 17A having the same shape face each other and bonding the parts atthe tire equatorial plane portion, wherein each of the parts isintegrally formed by injection molding or the like and includes one beadportion 12, one side portion 14 and a half-width crown portion 16. Thethermoplastic resin material according to the eleventh aspect of theinvention includes a polyamide-based thermoplastic elastomer and thespecific copolymer.

Meanwhile, the tire case 17 is not limited to a tire case formed bybonding two members, and may be formed by bonding three or more members.

(Effects)

In the tire 10 of the present embodiment, since the tire case 17 isformed of the thermoplastic resin material according to the eleventhaspect of the invention, the impact resistance is excellent, and thetemperature dependency of the tensile yield strength is suppressed.Furthermore, since the tire structure can be simplified, the weight islight compared to rubber of the related art. Therefore, when the tire 10of the present embodiment is applied to an automobile, the durability isexcellent, and the tire is unlikely to be deformed due to a change intemperature or the like. In addition, since the weight of the tire canbe decreased, it is possible to improve the fuel consumption of anautomobile in which the tire is used.

In addition, the polyamide-based thermoplastic elastomer, which is oneof the components of the thermoplastic resin material, has high adhesionproperties to the reinforcing cord 26, and, furthermore, is excellent interms of fixing performances, such as weld strength. Therefore, it ispossible to suppress the phenomenon in which air remains around thereinforcing cord 26 in the reinforcing cord winding process(incorporation of air). When the adhesion properties and weldability tothe reinforcing cord 26 are high, and, furthermore, incorporation of airinto the periphery of the reinforcing cord member is suppressed, it ispossible to effectively suppress the movement of the reinforcing cord 26caused by a force applied thereto at the time of driving or the like.Thereby, for example, even when a tire-constituting member has beenprovided so as to cover the entirety of the reinforcing cord member onthe outer circumference of the tire frame, since the movement of thereinforcing cord member is suppressed, the separation or the like of themembers (including the tire frame) is suppressed, and the durability ofthe tire 10 is improved.

In addition, in the tire 10 of the present embodiment, since thereinforcing cord 26 having a higher stiffness than the thermoplasticresin material is helically wound in the circumferential direction onthe outer circumferential surface of the crown portion 16 in the tirecase 17 formed of the thermoplastic resin material, the punctureresistance, the cutting resistance and the stiffness of the tire 10 inthe circumferential direction are improved. Meanwhile, the improvementof the stiffness of the tire 10 in the circumferential directionprevents the creeping in the tire case 17 formed of the thermoplasticresin material.

In addition, in the cross-sectional view of the tire case 17 along theaxial direction (the cross section illustrated in FIG. 1), since atleast a portion of the reinforcing cord 26 is embedded in the outercircumferential surface of the crown portion 16 in the tire case 17formed of the thermoplastic resin material, and is adhered to thethermoplastic resin material, incorporation of air during manufacturingis suppressed, and the movement of the reinforcing cord 26 caused by aforce applied thereto at the time of driving or the like is suppressed.Thereby, the separation or the like of the reinforcing cord 26, the tirecase 17 and the tread 30 is suppressed, and the durability of the tire10 is improved.

In addition, since the depth L of embedding of the reinforcing cord 26is ⅕ or more of the diameter D as illustrated in FIG. 2, incorporationof air during manufacturing is effectively suppressed, and the movementof the reinforcing cord 26 caused by a force applied thereto at the timeof driving or the like is further suppressed.

When the reinforcing cord layer 28 is configured to include thethermoplastic resin material as described above, since it is possible todecrease the difference in hardness between the tire case 17 and thereinforcing cord layer 28 compared to the case when the reinforcing cord26 is fixed using cushion rubber, the reinforcing cord 26 can be furtheradhered and fixed to the tire case 17. Thereby, the above incorporationof air can be effectively prevented, and it is possible to effectivelysuppress the movement of the reinforcing cord member at the time ofdriving.

Furthermore, when the reinforcing cord is a steel cord, since thereinforcing cord 26 can be easily separated and collected from thethermoplastic resin material through heating when disposing of the tire,it is advantageous in terms of the recycling properties of the tire 10.In addition, the resin material generally has a low loss factor (Tan δ)compared to vulcanized rubber. Therefore, when the reinforcing cordlayer includes a large amount of the resin material, it is possible toimprove the rolling properties of the tire. Furthermore, the resinmaterial having a relatively high elastic modulus compared to vulcanizedrubber is advantageous in that the in-plane shear stiffness is large,and steering stability and abrasion resistance during driving with thetire are also excellent.

In addition, since the tread 30 that comes into contact with roadsurfaces is made of a rubber material that is more abrasion-resistantthan the thermoplastic resin material, the abrasion resistance of thetire 10 is improved.

Furthermore, since an annular bead core 18 made of a metallic materialis embedded in the bead portion 12, the tire case 17, that is, the tire10 is strongly held to the rim 20 similarly to a pneumatic rubber tireof the related art.

In addition, furthermore, since the sealing layer 24 made of a rubbermaterial having higher sealing properties than the thermoplastic resinmaterial is provided in a portion, which comes into contact with the rim20, of the bead portion 12, the sealing properties between the tire 10and the rim 20 are improved. Therefore, compared to the case whensealing is carried out between the rim 20 and the thermoplastic resinmaterial, the air leakage from the tire is further suppressed. Inaddition, the rim fitting properties are also improved when the sealinglayer 24 is provided.

The above embodiment employs a configuration in which the reinforcingcord 26 is heated, and the thermoplastic resin material in the portionwith which the heated reinforcing cord 26 comes into contact is meltedor softened, but the eleventh aspect of the invention is not limited tothis configuration, and the reinforcing cord 26 may be embedded in thecrown portion 16 after heating the outer circumferential surface of thecrown portion 16, in which the reinforcing cord 26 is to be embedded,using a hot air generating apparatus without heating the reinforcingcord 26.

In addition, in Embodiment 11-1, a heater and a fan are used as the heatsource of a cord heating device 59, but the eleventh aspect of theinvention is not limited to this configuration, and a configuration inwhich the reinforcing cord 26 is directly heated using radiation heat(for example, infrared rays or the like) may be employed.

Furthermore, Embodiment 11-1 employs a configuration in which theportion, in which the thermoplastic resin material having thereinforcing cord 26 embedded therein is melted or softened, is forciblycooled using the second metal roller 64, but the eleventh aspect of theinvention is not limited to this configuration, and a configuration inwhich the portion, in which the thermoplastic resin material is meltedor softened, is forcibly cooled and solidified by directly blowing coldair to the portion in which the thermoplastic resin material is meltedor softened may be employed.

In addition, Embodiment 11-1 employs a configuration in which thereinforcing cord 26 is heated; however, for example, a configuration inwhich the outer circumference of the reinforcing cord 26 is coated withthe same thermoplastic resin material as the tire case 17 may beemployed, and, in this case, it is possible to effectively suppressincorporation of air during embedding in the crown portion 16 by heatingthe reinforcing cord 26 and the coating of the thermoplastic resinmaterial when winding the coated reinforcing cord around the crownportion 16 of the tire case 17.

In addition, the helical winding of the reinforcing cord 26 is easy inthe manufacturing, but a method, in which the reinforcing cord 26 isformed to be discontinuous in the width direction, or the like can bealso considered.

The tire 10 of Embodiment 11-1 is a so-called tubeless tire in which anair chamber is formed between the tire 10 and the rim 20 by mounting thebead portion 12 on the rim 20, but the eleventh aspect of the inventionis not limited to this configuration, and the tire may have a completetube shape.

The tire having the complete tube shape may be a configuration in which,for example, three tire frames formed into a circular shape are disposedin the tire width direction as illustrated in FIG. 4. FIG. 4 is across-sectional view of the tire according to other embodiment. Asillustrated in FIG. 4, the tire 86 has the tread rubber layer 87, hollowtubes (tire frame) 88 which are made of the same resin material as inEmbodiment 11-1 and are formed into the circular shape, the belt(reinforcing cord) 89 and the rim 90. Three tubes 88 are disposed inseries in the tire width direction of the tire 86. The tread rubberlayer 87, in which the belt 89 is embedded, is adhered to the outercircumferences of the tubes 88. In addition, the tubes 88 are mounted onthe rim 90 having recess portions that engage with the tubes 88.Meanwhile, the bead core is not provided in the tire 86.

Thus far, an embodiment of the eleventh aspect of the invention has beendescribed using the embodiment, but the embodiment is simply an example,and the invention can be carried out with a variety of modificationswithin the scope of the purport. In addition, it is needless to say thatthe scope of right of the eleventh aspect of the invention is notlimited to the above embodiment.

Embodiment 11-2

Next, the tire and the method of manufacturing the tire of the eleventhaspect of the invention according to Embodiment 11-2 will be describedaccording to the drawings. Similarly to the above Embodiment 11-1, thetire of the present embodiment exhibits substantially the samecross-sectional shape as an ordinary pneumatic rubber tire of therelated art. Here, the tire according to Embodiment 11-2 is the same asthe above Embodiment 1-2 except for the following points. Therefore, thesame reference numerals and drawings will be used in the descriptionregarding the same drawings and members.

In the tire of Embodiment 11-2, similarly to the above Embodiment 11-1,the tire case 17 is formed of a thermoplastic resin material made of amixed material of a polyamide-based thermoplastic elastomer (“UBESTA,XPA9055X1” manufactured by Ube Industries, Ltd.) and a Zn ionomer of anethylene-methacrylic acid copolymer (“HIMILAN, 1855Zn” manufactured byDu Pont-Mitsui Polychemicals Co., Ltd.).

In addition, the elastic modulus of the resin material for coating 27 ispreferably set in a range of 0.1 times to 10 times the elastic modulusof a resin material that forms the tire case 17. When the elasticmodulus of the resin material for coating 27 is 10 times or less theelastic modulus of the thermoplastic resin material that forms the tirecase 17, the crown portion does not become too hard, and fitting onto arim can be easily carried out. In addition, when the elastic modulus ofthe resin material for coating 27 is 0.1 times or more the elasticmodulus of the thermoplastic resin material that forms the tire case 17,the resin as a component of the reinforcing cord layer 28 does notbecome too soft, and the belt in-plane shear stiffness is excellent andthe cornering force is improved. Meanwhile, in the present embodiment,as the resin material for coating 27, the same material as thethermoplastic resin material (in the present embodiment, a thermoplasticresin material made of a mixed material of a polyamide-basedthermoplastic elastomer (“UBESTA, XPA9055X1” manufactured by UbeIndustries, Ltd.) and a Zn ionomer of an ethylene-methacrylic acidcopolymer (“HIMILAN, 1855Zn” manufactured by Du Pont-MitsuiPolychemicals Co., Ltd.)) is used. Other points are the same as in thetire according to the above Embodiment 1-2, and the manufacturing methodis also the same.

(Effects)

In the tire 200 of the present embodiment, since the tire case 17 isformed of the thermoplastic resin material, the impact resistance isexcellent, and the temperature dependency of the tensile yield strengthis suppressed. Therefore, when the tire 10 of the present embodiment isapplied to an automobile, the durability is excellent, and the tire isunlikely to be deformed due to a change in temperature or the like.

Furthermore, since the tire structure can be simplified, the weight islight compared to rubber of the related art. Therefore, since the weightof the tire 200 of the present embodiment can be decreased, it ispossible to improve the fuel consumption of an automobile in which thetire is used.

In addition, when the reinforcing cord layer 28 is configured to includethe coated cord member 26B, since it is possible to decrease thedifference in hardness between the tire case 17 and the reinforcing cordlayer 28 compared to the case when the reinforcing cord 26A is simplyfixed using cushion rubber 29, the coated cord member 26B can be furtheradhered and fixed to the tire case 17. Thereby, the above incorporationof air can be effectively prevented, and it is possible to effectivelysuppress the movement of the reinforcing cord member at the time ofdriving.

Furthermore, when the reinforcing cord is a steel cord, since the cordmember 26A can be easily separated and collected from the coated cordmember 26B through heating when disposing of the tire, it isadvantageous in terms of the recycling properties of the tire 200. Inaddition, the resin material generally has a low loss factor (Tan δ)compared to vulcanized rubber. Therefore, when the reinforcing cordlayer includes a large amount of the resin material, it is possible toimprove the rolling properties of the tire. Furthermore, the resinmaterial having a relatively high elastic modulus compared to vulcanizedrubber is advantageous in that the in-plane shear stiffness is large,and steering stability and abrasion resistance during driving with thetire are also excellent.

In the method of manufacturing the tire of the present embodiment, whenthe tire case 17, the cushion rubber 29 and a tread rubber 30A areintegrated, since the outer circumferential surface 17S of the tire case17 has been subjected to a roughening treatment, the bonding properties(adhesion properties) are improved due to the anchor effect. Inaddition, since the resin material that forms the tire case 17 is dug upby the collision of a blasting abrasive, the wettability of a bondingagent is improved. Thereby, a state in which the bonding agent isuniformly coated on the outer circumferential surface 17S of the tirecase 17 is held, and the bonding strength between the tire case 17 andthe cushion rubber 29 can be ensured.

Particularly, even when protrusions and recesses are formed on the outercircumferential surface 17S of the tire case 17, the peripheries of therecess portions (recess walls and recess bottoms) are subjected to aroughening treatment by making the blasting abrasive collide with therecess portions (voids 28A), and the bonding strength between the tirecase 17 and the cushion rubber 29 can be ensured.

Meanwhile, since the cushion rubber 29 is laminated in theroughening-treated areas on the outer circumferential surface 17S of thetire case 17, the bonding strength between the tire case 17 and thecushion rubber can be effectively ensured.

When the cushion rubber 29 has been vulcanized in a vulcanizing process,the cushion rubber 29 flows into the roughened recesses and protrusionsformed on the outer circumferential surface 17S of the tire case 17through the roughening treatment. In addition, when vulcanization iscompleted, the anchor effect is developed due to the cushion rubber 29flowing into the roughened recesses and protrusions so that the bondingstrength between the tire case 17 and the cushion rubber 29 is improved.

The tire 200 manufactured using the above method of manufacturing a tireensures the bonding strength between the tire case 17 and the cushionrubber 29, that is, ensures the bonding strength between the tire case17 and the tread 30 through the cushion rubber 29. Thereby, theseparation between the outer circumferential surface 17S of the tirecase 17 of the tire 200 and the cushion rubber 29 is suppressed at thetime of driving or the like.

In addition, since the outer circumference of the tire case 17 is madeof the reinforcing cord layer 28, the puncture resistance and thecutting resistance are improved compared to a case in which the outercircumference is made of something other than the reinforcing cord layer28.

In addition, since the reinforcing cord layer 28 is formed by windingthe coated cord member 26B, the stiffness of the tire 200 in thecircumferential direction is improved. The improvement of the stiffnessin the circumferential direction suppresses creeping (a phenomenon inwhich the plastic deformation of the tire case 17 increases over timeunder a constant stress) in the tire case 17, and the pressureresistance with respect to the air pressure from the inside in the tireradial direction is improved.

In the present embodiment, the recesses and protrusions are formed onthe outer circumferential surface 17S of the tire case 17, but theeleventh aspect of the invention is not limited thereto, and aconfiguration in which the outer circumferential surface 17S is formedto be flat may be employed.

In addition, in the tire case 17, the reinforcing cord layer may beformed by covering the coated cord member, which is wound around andbonded to the crown portion of the tire case, with a thermoplasticmaterial for coating. In this case, a coating layer can be formed bydischarging a thermoplastic material for coating in a molten or softenedstate on the reinforcing cord layer 28. In addition, the coating layermay be formed by heating a welding sheet into a molten or softened statewithout using an extruder, and attaching the welding sheet to thesurface (outer circumferential surface) of the reinforcing cord layer28.

The above Embodiment 11-2 employs a configuration in which case dividedparts (tire case half parts 17A) are bonded so as to form the tire case17, but the eleventh aspect of the invention is not limited thereto, andthe tire case 17 may be integrally formed using a mold or the like.

The tire 200 of Embodiment 11-2 is a so-called tubeless tire in which anair chamber is formed between the tire 200 and the rim 20 by mountingthe bead portion 12 on the rim 20, but the eleventh aspect of theinvention is not limited to this configuration, and the tire 200 mayhave, for example, a complete tube shape (for example, the shapeillustrated in FIG. 4).

In Embodiment 11-2, the cushion rubber 29 is disposed between the tirecase 17 and the tread 30, but the eleventh aspect of the invention isnot limited thereto, and a configuration in which the cushion rubber 29is not disposed may be employed.

In addition, Embodiment 11-2 employs a configuration in which the coatedcord member 26B is helically wound around the crown portion 16, but theeleventh aspect of the invention is not limited thereto, and aconfiguration in which the coated cord member 26B is wound to bediscontinuous in the width direction may be employed.

Embodiment 11-2 employs a configuration in which a thermoplasticmaterial is used as the resin material for coating 27 that forms thecoated cord member 26B, and the resin material for coating 27 is heatedinto a molten or softened state so as to weld the coated cord member 26Bon the outer circumferential surface of the crown portion 16, but theeleventh aspect of the invention is not limited to this configuration,and a configuration in which the coated cord member 26B is adhered tothe outer circumferential surface of the crown portion 16 using anadhesive or the like without heating the resin material for coating 27may be employed.

In addition, a configuration in which a thermosetting resin is used asthe resin material for coating 27 that forms the coated cord member 26B,and the coated cord member 26B is adhered to the outer circumferentialsurface of the crown portion 16 using an adhesive or the like withoutheating may be employed.

Furthermore, a configuration in which a thermosetting resin is used asthe resin material for coating 27 that forms the coated cord member 26B,and the tire case 17 is formed of a thermoplastic resin material may beemployed. In this case, the coated cord member 26B may be adhered to theouter circumferential surface of the crown portion 16 using an adhesiveor the like, or the coated cord member 26B may be welded on the outercircumferential surface of the crown portion 16 by heating the portion,which is to be provided with the coated cord member 26B, of the tirecase 17 into a molten or softened state.

In addition, furthermore, a configuration in which a thermoplasticmaterial is used as the resin material for coating 27 that forms thecoated cord member 26B, and the tire case 17 is formed of athermoplastic resin material may be employed. In this case, the coatedcord member 26B may be adhered to the outer circumferential surface ofthe crown portion 16 using an adhesive or the like, or the coated cordmember 26B may be welded on the outer circumferential surface of thecrown portion 16 by heating the portion, which is to be provided withthe coated cord member 26B, of the tire case 17 into a molten orsoftened state, and heating the resin material for coating 27 into amolten or softened state. Meanwhile, when both the tire case 17 and thecoated cord member 26B have been heated into a molten or softened state,since both are well mixed, the bonding strength is improved. Inaddition, when thermoplastic resin materials are used as both the resinmaterial that forms the tire case 17 and the resin material for coating27 that forms the coated cord member 26B, the thermoplastic resinmaterials are preferably the same kind of thermoplastic materials,particularly, the same thermoplastic material.

In addition, furthermore, an adhesive may be coated on the outercircumferential surface 17S of the tire case 17, after the surface ofthe outer circumferential surface 17S, on which the roughening treatmenthas been carried out, is activated using a corona treatment, a plasmatreatment or the like so as to increase the hydrophilicity.

In addition, furthermore, the order for manufacturing the tire 200 isnot limited to the order in Embodiment 11-2, and may be appropriatelychanged.

Thus far, an embodiment of the eleventh aspect of the invention has beendescribed using the embodiment, but the embodiment is simply an example,and the invention can be carried out with a variety of modificationswithin the scope of the purport. In addition, it is needless to say thatthe scope of right of the eleventh aspect of the invention is notlimited to the above embodiment.

Thus far, the specific embodiments according to the eleventh aspect ofthe invention have been described using Embodiment 11-1 and Embodiment11-2, but the eleventh aspect of the invention is not limited to theabove embodiments.

<<The Twelfth Aspect of the Invention>>

Next, a thermoplastic resin material that constitutes the tire frame inthe twelfth aspect of the invention will be described, and,subsequently, a specific embodiment of the tire of the twelfth aspect ofthe invention will be described using the drawings.

[Thermoplastic Resin Material]

The tire of the twelfth aspect of the invention is a tire including atleast a circular tire frame formed of a thermoplastic resin material, inwhich the thermoplastic resin material contains a polyamide-basedthermoplastic elastomer, an olefin-(meth)acrylic acid copolymer(specific copolymer) and an acid-modified copolymer formed byacid-modifying an olefin-(meth)acrylate copolymer (specificacid-modified copolymer).

Since a polyamide-based thermoplastic elastomer, the specific copolymerand the specific acid-modified copolymer are contained in thethermoplastic resin material according to the twelfth aspect of theinvention, a tire can be obtained in which the impact resistance andfracture resistance are excellent when the thermoplastic resin materialaccording to the twelfth aspect of the invention is applied to the tire.

Hereinafter, the polyamide-based thermoplastic elastomer, the specificcopolymer and the specific acid-modified copolymer will be described.

(Polyamide-Based Thermoplastic Elastomer)

The “thermoplastic elastomer” is a thermoplastic resin materialincluding a hard segment and a soft segment in the molecule as describedabove, and, in detail, refers to an elastic macromolecular compound,which is a thermoplastic resin material made of a copolymer including apolymer that constitutes a crystalline hard segment having a highmelting point or a hard segment forming a pseudo-crosslink throughphysical aggregation, and a polymer that constitutes a non-crystallinesoft segment having a low glass transition temperature.

In addition, the “polyamide-based thermoplastic elastomer” is an elasticmacromolecular compound, and refers to a thermoplastic resin materialwhich is made of a copolymer including a polymer that constitutes acrystalline hard segment having a high melting point, and a polymer thatconstitutes a non-crystalline soft segment having a low glass transitiontemperature, and which has an amide bond (—CONH—) in the main chain ofthe polymer that constitutes the hard segment.

Examples of crystalline polyamide that constitutes the hard segmentinclude aliphatic polyamides, such as polycaproamide (nylon-6),poly-ω-aminoheptanoic acid (nylon-7), poly-ω-aminononanoic acid(nylon-9), polyundecaneamide (nylon-11), polylauryl lactam (nylon-12),polyethylene diamine adipamide (nylon-2,6), polytetramethylene adipamide(nylon-4,6), polyhexamethylene adipamide (nylon-6,6), polyhexamethylenesebacamide (nylon-6,10), polyhexamethylene dodecamide (nylon-6,12),polyoctamethylene adipamide (nylon-8,6) and polydecamethylene adipamide(nylon-10,8); crystalline aromatic polyamides obtained through apolycondensation reaction between an aromatic diamine, such asmeta-xylene diamine or para-xylene diamine, and a dicarboxylic acid,such as adipic acid, suberic acid, sebacic acid, cyclohexanedicarboxylic acid, terephthalic acid or isophthalic acid, or aderivative thereof; and the like.

Among the above, nylon-6, nylon-6,6, nylon-12 and the like arepreferable, and nylon-12 is more preferable. As the “polyamide-basedthermoplastic elastomer” in the present embodiment, the samepolyamide-based thermoplastic elastomer as in the above first aspect ofthe invention can be used.

[Specific Copolymer]

The thermoplastic resin material contains an olefin-(meth)acrylic acidcopolymer (specific copolymer).

Here, the “olefin-(meth)acrylic acid copolymer” refers to a copolymerincluding a partial structure derived from (meth)acrylic acid in therepeating unit of an olefin. The “(meth)acrylic acid” refers to at leastone of acrylic acid or methacrylic acid. The form of the copolymer maybe a radical polymer, a block copolymer or a graft copolymer.

In the olefin-(meth)acrylic acid copolymer, the olefin that constitutesthe repeating unit of the olefin is preferably ethylene, propylene or1-butene, and is more preferably ethylene.

That is, the olefin-(meth)acrylic acid copolymer is preferably anethylene-(meth)acrylic acid copolymer, and more preferably anethylene-methacrylic acid copolymer.

The olefin-(meth)acrylic acid copolymer may be used solely, or may beused in combination of two or more kinds.

The number average molecular weight (Mn) of the specific copolymer ispreferably 5,000 to 10,000,000, and more preferably 7,000 to 1,000,000from the viewpoint of the melt moldability of the thermoplastic resinmaterial.

As the olefin, an ethylene is preferable, and, furthermore, as thespecific copolymer, an ethylene-methacrylic acid copolymer ispreferable.

A commercially available product may be used as the specific copolymer,and examples thereof include NUCREL manufactured by Du Pont-MitsuiPolychemicals Co., Ltd. (N035C, AN42115C, and the like).

[Specific Acid-Modified Copolymer]

The thermoplastic resin material contains an acid-modified copolymerformed by acid-modifying an olefin-(meth)acrylate copolymer (specificacid-modified copolymer).

Here, the “acid-modified copolymer formed by acid-modifying anolefin-(meth)acrylate copolymer” refers to a copolymer obtained bybonding a compound having an acid group to a copolymer [that is, anolefin-(meth)acrylate copolymer] including a partial structure derivedfrom (meth)acrylate in the repeating unit of an olefin. The“(meth)acrylate” refers to at least one of acrylate or methacrylate.

The “bonding a compound having an acid group to an olefin-(meth)acrylatecopolymer” more specifically refers to bonding an unsaturated compoundhaving an acid group, such as a carboxylic acid group, a sulfuric acidgroup or a phosphoric acid group, to the olefin-(meth)acrylatecopolymer. Examples thereof include bonding (for example, graftpolymerizing) an unsaturated bond portion in an unsaturated carboxylicacid to the olefin-(meth)acrylate copolymer when an unsaturatedcarboxylic acid (generally maleic anhydride) is used as the unsaturatedcompound having an acid group.

The compound having an acid group is preferably a compound having acarboxylic acid group (carboxy group), which is a weak acid group, fromthe viewpoint of suppressing the deterioration of theolefin-(meth)acrylate copolymer, and examples thereof include an acrylicacid, a methacrylic acid, an itaconic acid, a crotonic acid, anisocrotonic acid, a maleic acid, and the like.

In the olefin-(meth)acrylate copolymer, the olefin that constitutes therepeating unit of the olefin is preferably ethylene, propylene or1-butene, and is more preferably ethylene.

That is, the olefin-(meth)acrylate copolymer is preferably anethylene-(meth)acrylate copolymer.

Accordingly, as the specific acid-modified copolymer, an acid-modifiedproduct of an ethylene-(meth)acrylate copolymer is preferable, acarboxylic acid-modified copolymer formed by acid-modifying anethylene-(meth)acrylate ethyl ester copolymer using a compound having acarboxylic acid group (carboxy group) is more preferable, and acarboxylic acid-modified product of an ethylene-acrylate ethyl estercopolymer is still more preferable.

The specific acid-modified copolymer may be used solely, or may be usedin combination of two or more kinds.

The number average molecular weight (Mn) of the specific acid-modifiedcopolymer is preferably 5,000 to 10,000,000, and more preferably 7,000to 1,000,000 from the viewpoint of the melt moldability of thethermoplastic resin material.

A commercially available product may be used as the specificacid-modified copolymer, and examples thereof include HPR manufacturedby Du Pont-Mitsui Polychemicals Co., Ltd. (AR2011 and the like).

The mass ratio (x:y+z) between the polyamide-based thermoplasticelastomer (x) and the specific copolymer (y) and the specificacid-modified copolymer (z) in the thermoplastic resin material ispreferably from 95:5 to 50:50, and more preferably from 90:10 to 50:50from the viewpoint of impact resistance and fracture properties.

In addition, the mass ratio (y:z) between the specific copolymer (y) andthe specific acid-modified copolymer (z) in the thermoplastic resinmaterial is preferably from 95:5 to 10:90, and more preferably from80:20 to 20:80. Setting the mass ratio in the above range enables thesufficient development of the performances of the thermoplastic resinmaterial, and it is possible to improve the tensile characteristics,such as tensile elasticity, breaking strength and fracture properties,as the tire performances. Meanwhile, a combination of anethylene-methacrylic acid copolymer and an acid-modified product of anethylene-acrylate copolymer is preferably used as the specific copolymerand the specific acid-modified copolymer.

Furthermore, in the thermoplastic resin material, the total content ofthe thermoplastic elastomer, the specific copolymer and the specificacid-modified copolymer in the thermoplastic resin material ispreferably 50 mass % to 100 mass %, and more preferably 50 mass % to 90mass % with respect to the total mass of the thermoplastic resinmaterial from the viewpoint of sufficiently developing the performancesof the thermoplastic resin material.

The thermoplastic resin material may contain a variety of fillers (forexample, silica, calcium carbonate and clay) and a variety of additives,such as an age inhibitor, oil, a plasticizer, a coloring agent, aweather-resisting agent and a reinforcing material, as desired.

The thermoplastic resin material can be obtained by mixing thethermoplastic elastomer, the specific copolymer and the specificacid-modified copolymer, adding a variety of additives as necessary, andmelting and mixing the components. The mixing ratio between thethermoplastic elastomer, the specific copolymer and the specificacid-modified copolymer is based on the ratio described above. Thethermoplastic resin material obtained through melting and mixing can beused in a pellet shape as necessary.

The tensile modulus of elasticity (in the specification, the “elasticmodulus” refers to the tensile modulus of elasticity unless particularlyotherwise described), which is defined in JIS K7113:1995, of thethermoplastic resin material according to the twelfth aspect of theinvention is preferably 100 MPa to 1000 MPa, more preferably 100 MPa to800 MPa, and particularly preferably 100 MPa to 700 MPa. When thetensile modulus of elasticity of the thermoplastic resin material is 100MPa to 1000 MPa, fitting onto a rim can be efficiently carried out whileholding the shape of the tire frame.

The tensile yield strength, which is defined in JIS K7113:1995, of thethermoplastic resin material according to the twelfth aspect of theinvention is preferably 5 MPa or more, preferably 5 MPa to 20 MPa, andstill more preferably 5 MPa to 17 MPa. When the tensile yield strengthof the thermoplastic resin material is 5 MPa or more, it is possible towithstand deformation caused by a load applied to the tire at the timeof driving or the like.

The tensile yield elongation, which is defined in JIS K7113:1995, of thethermoplastic resin material according to the twelfth aspect of theinvention is preferably 10% or more, preferably 10% to 70%, and stillmore preferably 15% to 60%. When the tensile yield elongation of thethermoplastic resin material is 10% or more, it is possible to increasethe elastic region and improve the fittability onto a rim.

The tensile elongation at break (JIS K7113:1995), which is defined inJIS K7113:1995, of the thermoplastic resin material according to thetwelfth aspect of the invention is preferably 50% or more, preferably100% or more, still more preferably 150% or more, and particularlypreferably 200% or more. When the tensile elongation at break of thethermoplastic resin material is 50% or more, it is possible to improvethe fittability onto a rim and avoid fracture due to collision.

The deflection temperature under load (under a load of 0.45 MPa), whichis defined in ISO75-2 or ASTM D648, of the thermoplastic resin materialaccording to the twelfth aspect of the invention is preferably 50° C. ormore, preferably 50° C. to 150° C., and still more preferably 50° C. to130° C. When the deflection temperature under load of the thermoplasticresin material is 50° C. or more, it is possible to suppress deformationin a vulcanization process of a tread or the like.

[The Resin Material as a Component of the Reinforcing Cord Layer]

The tire of the twelfth aspect of the invention may have the reinforcingcord member which is wound around the outer circumference of the tireframe in the circumferential direction so as to form the reinforcingcord layer.

The “resin material as a component of the reinforcing cord layer”according to the twelfth aspect of the invention is the same as the[resin material as a component of the reinforcing cord layer] accordingto the first aspect of the invention.

Embodiment 12-1

Hereinafter, a tire according to Embodiment 12-1 of the tire of thetwelfth aspect of the invention will be described according to thedrawings.

Here, the tire according to Embodiment 12-1 is the same as the aboveEmbodiment 12 except for the following points. Therefore, the samereference numerals and drawings will be used in the descriptionregarding the same drawings and members.

The tire case 17 of the present embodiment is formed of a thermoplasticresin material made of a mixed material of a polyamide-basedthermoplastic elastomer (“UBESTA, XPA9055X1” manufactured by UbeIndustries, Ltd.), the specific copolymer (an ethylene-methacrylic acidcopolymer “NUCREL, N035C” manufactured by Du Pont-Mitsui PolychemicalsCo., Ltd.) and the specific acid-modified copolymer (an acid-modifiedproduct of an ethylene-acrylate ethyl ester copolymer “HPR, AR2011”manufactured by Du Pont-Mitsui Polychemicals Co., Ltd.). In the presentembodiment, the tire case 17 is formed of the thermoplastic resinmaterial according to the twelfth aspect of the invention alone, but thetwelfth aspect of the invention is not limited to this configuration,and, similarly to an ordinary pneumatic rubber tire of the related art,other thermoplastic resin materials having different characteristics maybe used in the respective portions (the side portions 14, the crownportion 16, the bead portions 12, and the like) of the tire case 17.Other points are the same as in the tire according to the aboveEmbodiment 12, and the manufacturing method is also the same.

(Effects)

In the tire 10 of the present embodiment, since the tire case 17 isformed of the thermoplastic resin material according to the twelfthaspect of the invention, the impact resistance and the fractureproperties are excellent. Furthermore, since the tire structure can besimplified, the weight is light compared to rubber of the related art.Therefore, when the tire 10 of the present embodiment is applied to anautomobile, the durability is excellent. In addition, since the weightof the tire can be decreased, it is possible to improve the fuelconsumption of an automobile in which the tire is used.

In addition, the polyamide-based thermoplastic elastomer, which is oneof the components of the thermoplastic resin material, has high adhesionproperties to the reinforcing cord 26, and, furthermore, is excellent interms of fixing performances, such as weld strength. Therefore, it ispossible to suppress the phenomenon in which air remains around thereinforcing cord 26 in the reinforcing cord winding process(incorporation of air). When the adhesion properties and weldability tothe reinforcing cord 26 are high, and, furthermore, incorporation of airinto the periphery of the reinforcing cord member is suppressed, it ispossible to effectively suppress the movement of the reinforcing cord 26caused by a force applied thereto at the time of driving or the like.Thereby, for example, even when a tire-constituting member has beenprovided so as to cover the entirety of the reinforcing cord member onthe outer circumference of the tire frame, since the movement of thereinforcing cord member is suppressed, the separation or the like of themembers (including the tire frame) is suppressed, and the durability ofthe tire 10 is improved.

In addition, in the tire 10 of the present embodiment, since thereinforcing cord 26 having a higher stiffness than the thermoplasticresin material is helically wound in the circumferential direction onthe outer circumferential surface of the crown portion 16 in the tirecase 17 formed of the thermoplastic resin material, the punctureresistance, the cutting resistance and the stiffness of the tire 10 inthe circumferential direction are improved. Meanwhile, the improvementof the stiffness of the tire 10 in the circumferential directionprevents the creeping in the tire case 17 formed of the thermoplasticresin material.

In addition, in the cross-sectional view of the tire case 17 along theaxial direction (the cross section illustrated in FIG. 1), since atleast a portion of the reinforcing cord 26 is embedded in the outercircumferential surface of the crown portion 16 in the tire case 17formed of the thermoplastic resin material, and is adhered to thethermoplastic resin material, incorporation of air during manufacturingis suppressed, and the movement of the reinforcing cord 26 caused by aforce applied thereto at the time of driving or the like is suppressed.Thereby, the separation or the like of the reinforcing cord 26, the tirecase 17 and the tread 30 is suppressed, and the durability of the tire10 is improved.

In addition, since the depth L of embedding of the reinforcing cord 26is ⅕ or more of the diameter D as illustrated in FIG. 2, incorporationof air during manufacturing is effectively suppressed, and the movementof the reinforcing cord 26 caused by a force applied thereto at the timeof driving or the like is further suppressed.

When the reinforcing cord layer 28 is configured to include thethermoplastic resin material as described above, since it is possible todecrease the difference in hardness between the tire case 17 and thereinforcing cord layer 28 compared to the case when the reinforcing cord26 is fixed using cushion rubber, the reinforcing cord 26 can be furtheradhered and fixed to the tire case 17. Thereby, the above incorporationof air can be effectively prevented, and it is possible to effectivelysuppress the movement of the reinforcing cord member at the time ofdriving.

Furthermore, when the reinforcing cord is a steel cord, since thereinforcing cord 26 can be easily separated and collected from thethermoplastic resin material through heating when disposing of the tire,it is advantageous in terms of the recycling properties of the tire 10.In addition, the resin material generally has a low loss factor (Tan δ)compared to vulcanized rubber. Therefore, when the reinforcing cordlayer includes a large amount of the resin material, it is possible toimprove the rolling properties of the tire. Furthermore, the resinmaterial having a relatively high elastic modulus compared to vulcanizedrubber is advantageous in that the in-plane shear stiffness is large,and steering stability and abrasion resistance during driving with thetire are also excellent.

In addition, since the tread 30 that comes into contact with roadsurfaces is made of a rubber material that is more abrasion-resistantthan the thermoplastic resin material, the abrasion resistance of thetire 10 is improved.

Furthermore, since an annular bead core 18 made of a metallic materialis embedded in the bead portion 12, the tire case 17, that is, the tire10 is strongly held to the rim 20 similarly to a pneumatic rubber tireof the related art.

In addition, furthermore, since the sealing layer 24 made of a rubbermaterial having higher sealing properties than the thermoplastic resinmaterial is provided in a portion, which comes into contact with the rim20, of the bead portion 12, the sealing properties between the tire 10and the rim 20 are improved. Therefore, compared to the case whensealing is carried out between the rim 20 and the thermoplastic resinmaterial, the air leakage from the tire is further suppressed. Inaddition, the rim fitting properties are also improved when the sealinglayer 24 is provided.

The above embodiment employs a configuration in which the reinforcingcord 26 is heated, and the thermoplastic resin material in the portionwith which the heated reinforcing cord 26 comes into contact is meltedor softened, but the twelfth aspect of the invention is not limited tothis configuration, and the reinforcing cord 26 may be embedded in thecrown portion 16 after heating the outer circumferential surface of thecrown portion 16, in which the reinforcing cord 26 is to be embedded,using a hot air generating apparatus without heating the reinforcingcord 26.

In addition, in Embodiment 12-1, a heater and a fan are used as the heatsource of a cord heating device 59, but the twelfth aspect of theinvention is not limited to this configuration, and a configuration inwhich the reinforcing cord 26 is directly heated using radiation heat(for example, infrared rays or the like) may be employed.

Furthermore, Embodiment 12-1 employs a configuration in which theportion, in which the thermoplastic resin material having thereinforcing cord 26 embedded therein is melted or softened, is forciblycooled using the second metal roller 64, but the twelfth aspect of theinvention is not limited to this configuration, and a configuration inwhich the portion, in which the thermoplastic resin material is meltedor softened, is forcibly cooled and solidified by directly blowing coldair to the portion in which the thermoplastic resin material is meltedor softened may be employed.

In addition, Embodiment 12-1 employs a configuration in which thereinforcing cord 26 is heated; however, for example, a configuration inwhich the outer circumference of the reinforcing cord 26 is coated withthe same thermoplastic resin material as the tire case 17 may beemployed, and, in this case, it is possible to effectively suppressincorporation of air during embedding in the crown portion 16 by heatingthe reinforcing cord 26 and the coating of the thermoplastic resinmaterial when winding the coated reinforcing cord around the crownportion 16 of the tire case 17.

In addition, the helical winding of the reinforcing cord 26 is easy inthe manufacturing, but a method, in which the reinforcing cord 26 isformed to be discontinuous in the width direction, or the like can bealso considered.

The tire 10 of Embodiment 12-1 is a so-called tubeless tire in which anair chamber is formed between the tire 10 and the rim 20 by mounting thebead portion 12 on the rim 20, but the twelfth aspect of the inventionis not limited to this configuration, and the tire may have a completetube shape.

The tire having the complete tube shape may be a configuration in which,for example, three tire frames formed into a circular shape are disposedin the tire width direction as illustrated in FIG. 4. FIG. 4 is across-sectional view of the tire according to other embodiment. Asillustrated in FIG. 4, the tire 86 has the tread rubber layer 87, hollowtubes (tire frame) 88 which are made of the same resin material as inEmbodiment 12-1 and are formed into the circular shape, the belt(reinforcing cord) 89 and the rim 90. Three tubes 88 are disposed inseries in the tire width direction of the tire 86. The tread rubberlayer 87, in which the belt 89 is embedded, is adhered to the outercircumferences of the tubes 88. In addition, the tubes 88 are mounted onthe rim 90 having recess portions that engage with the tubes 88.Meanwhile, the bead core is not provided in the tire 86.

Thus far, an embodiment of the twelfth aspect of the invention has beendescribed using the embodiment, but the embodiment is simply an example,and the invention can be carried out with a variety of modificationswithin the scope of the purport. In addition, it is needless to say thatthe scope of right of the twelfth aspect of the invention is not limitedto the above embodiment.

Embodiment 12-2

Next, the tire and the method of manufacturing the tire of the twelfthaspect of the invention according to Embodiment 12-2 will be describedaccording to the drawings. Similarly to the above Embodiment 12-1, thetire of the present embodiment exhibits substantially the samecross-sectional shape as an ordinary pneumatic rubber tire of therelated art. Here, the tire according to Embodiment 12-2 is the same asthe above Embodiment 1-2 except for the following points. Therefore, thesame reference numerals and drawings will be used in the descriptionregarding the same drawings and members.

In the tire of Embodiment 12-2, similarly to the above Embodiment 12-1,the tire case 17 is formed of a thermoplastic resin material made of amixed material of a polyamide-based thermoplastic elastomer (“UBESTA,XPA9055X1” manufactured by Ube Industries, Ltd.), the specific copolymer(an ethylene-methacrylic acid copolymer “NUCREL, N035C” manufactured byDu Pont-Mitsui Polychemicals Co., Ltd.) and the specific acid-modifiedcopolymer (an acid-modified product of an ethylene-acrylate ethyl estercopolymer “HPR, AR2011” manufactured by Du Pont-Mitsui PolychemicalsCo., Ltd.). Other points are the same as in the tire according to theabove Embodiment 1-2, and the manufacturing method is also the same.

In addition, the elastic modulus of a resin material for coating 27 ispreferably set in a range of 0.1 times to 10 times the elastic modulusof a resin material that forms the tire case 17. When the elasticmodulus of the resin material for coating 27 is 10 times or less theelastic modulus of the thermoplastic resin material that forms the tirecase 17, the crown portion does not become too hard, and fitting onto arim can be easily carried out. In addition, when the elastic modulus ofthe resin material for coating 27 is 0.1 times or more the elasticmodulus of the thermoplastic resin material that forms the tire case 17,the resin as a component of the reinforcing cord layer 28 does notbecome too soft, and the belt in-plane shear stiffness is excellent andthe cornering force is improved. Meanwhile, in the present embodiment,as the resin material for coating 27, the same material as thethermoplastic resin material [in the present embodiment, a thermoplasticresin material made of a mixed material of a polyamide-basedthermoplastic elastomer (“UBESTA, XPA9055X1” manufactured by UbeIndustries, Ltd.), the specific copolymer (an ethylene-methacrylic acidcopolymer “NUCREL, N035C” manufactured by Du Pont-Mitsui PolychemicalsCo., Ltd.) and the specific acid-modified copolymer (an acid-modifiedproduct of an ethylene-acrylate ethyl ester copolymer “HPR, AR2011”manufactured by Du Pont-Mitsui Polychemicals Co., Ltd.)] is used.

(Effects)

In the tire 200 of the present embodiment, since the tire case 17 isformed of the thermoplastic resin material, the impact resistance andthe fracture properties are excellent. Therefore, when the tire 10 ofthe present embodiment is applied to an automobile, the durability isexcellent.

Furthermore, since the tire structure can be simplified, the weight islight compared to rubbers of the related art. Therefore, since theweight of the tire 200 of the present embodiment can be decreased, it ispossible to improve the fuel consumption of an automobile in which thetire is used.

In addition, when the reinforcing cord layer 28 is configured to includethe coated cord member 26B, since it is possible to decrease thedifference in hardness between the tire case 17 and the reinforcing cordlayer 28 compared to the case when the reinforcing cord 26A is simplyfixed using cushion rubber 29, the coated cord member 26B can be furtheradhered and fixed to the tire case 17. Thereby, the above incorporationof air can be effectively prevented, and it is possible to effectivelysuppress the movement of the reinforcing cord member at the time ofdriving.

Furthermore, when the reinforcing cord is a steel cord, since the cordmember 26A can be easily separated and collected from the coated cordmember 26B through heating when disposing of the tire, it isadvantageous in terms of the recycling properties of the tire 200. Inaddition, the resin material generally has a low loss factor (Tan δ)compared to vulcanized rubber. Therefore, when the reinforcing cordlayer includes a large amount of the resin material, it is possible toimprove the rolling properties of the tire. Furthermore, the resinmaterial having a relatively high elastic modulus compared to vulcanizedrubber is advantageous in that the in-plane shear stiffness is large,and steering stability and abrasion resistance during driving with thetire are also excellent.

In the method of manufacturing the tire of the present embodiment, whenthe tire case 17, the cushion rubber 29 and a tread rubber 30A areintegrated, since the outer circumferential surface 17S of the tire case17 has been subjected to a roughening treatment, the bonding properties(adhesion properties) are improved due to the anchor effect. Inaddition, since the resin material that forms the tire case 17 is dug upby the collision of a blasting abrasive, the wettability of a bondingagent is improved. Thereby, a state in which the bonding agent isuniformly coated on the outer circumferential surface 17S of the tirecase 17 is held, and the bonding strength between the tire case 17 andthe cushion rubber 29 can be ensured.

Particularly, even when protrusions and recesses are formed on the outercircumferential surface 17S of the tire case 17, the peripheries of therecess portions (recess walls and recess bottoms) are subjected to aroughening treatment by making the blasting abrasive collide with therecess portions (voids 28A), and the bonding strength between the tirecase 17 and the cushion rubber 29 can be ensured.

Meanwhile, since the cushion rubber 29 is laminated in theroughening-treated areas on the outer circumferential surface 17S of thetire case 17, the bonding strength between the tire case 17 and thecushion rubber can be effectively ensured.

When the cushion rubber 29 has been vulcanized in a vulcanizing process,the cushion rubber 29 flows into the roughened recesses and protrusionsformed on the outer circumferential surface 17S of the tire case 17through the roughening treatment. In addition, when vulcanization iscompleted, the anchor effect is developed due to the cushion rubber 29that has flowed into the roughened recesses and protrusions so that thebonding strength between the tire case 17 and the cushion rubber 29 isimproved.

The tire 200 manufactured using the above method of manufacturing a tireensures the bonding strength between the tire case 17 and the cushionrubber 29, that is, ensures the bonding strength between the tire case17 and the tread 30 through the cushion rubber 29. Thereby, theseparation between the outer circumferential surface 17S of the tirecase 17 of the tire 200 and the cushion rubber 29 is suppressed at thetime of driving or the like.

In addition, since the outer circumference of the tire case 17 is madeof the reinforcing cord layer 28, the puncture resistance and thecutting resistance are improved compared to a case in which the outercircumference is made of something other than the reinforcing cord layer28.

In addition, since the reinforcing cord layer 28 is formed by windingthe coated cord member 26B, the stiffness of the tire 200 in thecircumferential direction is improved. The improvement of the stiffnessin the circumferential direction suppresses creeping (a phenomenon inwhich the plastic deformation of the tire case 17 increases over timeunder a constant stress) in the tire case 17, and the pressureresistance with respect to the air pressure from the inside in the tireradial direction is improved.

In the present embodiment, the recesses and protrusions are formed onthe outer circumferential surface 17S of the tire case 17, but thetwelfth aspect of the invention is not limited thereto, and aconfiguration in which the outer circumferential surface 17S is formedto be flat may be employed.

In addition, in the tire case 17, the reinforcing cord layer may beformed by covering the coated cord member, which is wound around andbonded to the crown portion of the tire case, with a thermoplasticmaterial for coating. In this case, a coating layer can be formed bydischarging a thermoplastic material for coating in a molten or softenedstate on the reinforcing cord layer 28. In addition, the coating layermay be formed by heating a welding sheet into a molten or softened statewithout using an extruder, and attaching the welding sheet to thesurface (outer circumferential surface) of the reinforcing cord layer28.

The above Embodiment 12-2 employs a configuration in which case dividedparts (tire case half parts 17A) are bonded so as to form the tire case17, but the twelfth aspect of the invention is not limited thereto, andthe tire case 17 may be integrally formed using a mold or the like.

The tire 200 of Embodiment 12-2 is a so-called tubeless tire in which anair chamber is formed between the tire 200 and the rim 20 by mountingthe bead portion 12 on the rim 20, but the twelfth aspect of theinvention is not limited to this configuration, and the tire 200 mayhave, for example, a complete tube shape (for example, the shapeillustrated in FIG. 4).

In Embodiment 12-2, the cushion rubber 29 is disposed between the tirecase 17 and the tread 30, but the twelfth aspect of the invention is notlimited thereto, and a configuration in which the cushion rubber 29 isnot disposed may be employed.

In addition, Embodiment 12-2 employs a configuration in which the coatedcord member 26B is helically wound around the crown portion 16, but thetwelfth aspect of the invention is not limited thereto, and aconfiguration in which the coated cord member 26B is wound to bediscontinuous in the width direction may be employed.

Embodiment 12-2 employs a configuration in which a thermoplasticmaterial is used as the resin material for coating 27 that forms thecoated cord member 26B, and the resin material for coating 27 is heatedinto a molten or softened state so as to weld the coated cord member 26Bon the outer circumferential surface of the crown portion 16, but thetwelfth aspect of the invention is not limited to this configuration,and a configuration in which the coated cord member 26B is adhered tothe outer circumferential surface of the crown portion 16 using anadhesive or the like without heating the resin material for coating 27may be employed.

In addition, a configuration in which a thermosetting resin is used asthe resin material for coating 27 that forms the coated cord member 26B,and the coated cord member 26B is adhered to the outer circumferentialsurface of the crown portion 16 using an adhesive or the like withoutheating may be employed.

Furthermore, a configuration in which a thermosetting resin is used asthe resin material for coating 27 that forms the coated cord member 26B,and the tire case 17 is formed of a thermoplastic resin material may beemployed. In this case, the coated cord member 26B may be adhered to theouter circumferential surface of the crown portion 16 using an adhesiveor the like, or the coated cord member 26B may be welded on the outercircumferential surface of the crown portion 16 by heating the portion,which is to be provided with the coated cord member 26B, of the tirecase 17 into a molten or softened state.

In addition, furthermore, a configuration in which a thermoplasticmaterial is used as the resin material for coating 27 that forms thecoated cord member 26B, and the tire case 17 is formed of athermoplastic resin material may be employed. In this case, the coatedcord member 26B may be adhered to the outer circumferential surface ofthe crown portion 16 using an adhesive or the like, or the coated cordmember 26B may be welded on the outer circumferential surface of thecrown portion 16 by heating the portion, which is to be provided withthe coated cord member 26B, of the tire case 17 into a molten orsoftened state, and heating the resin material for coating 27 into amolten or softened state. Meanwhile, when both the tire case 17 and thecoated cord member 26B have been heated into a molten or softened state,since both are well mixed, the bonding strength is improved. Inaddition, when thermoplastic resin materials are used as both the resinmaterial that forms the tire case 17 and the resin material for coating27 that forms the coated cord member 26B, the thermoplastic resinmaterials are preferably the same kind of thermoplastic materials,particularly, the same thermoplastic material.

In addition, furthermore, an adhesive may be coated on the outercircumferential surface 17S of the tire case 17, after the surface ofthe outer circumferential surface 17S, on which the roughening treatmenthas been carried out, is activated using a corona treatment, a plasmatreatment or the like so as to increase the hydrophilicity.

In addition, furthermore, the order for manufacturing the tire 200 isnot limited to the order in Embodiment 12-2, and may be appropriatelychanged.

Thus far, an embodiment of the twelfth aspect of the invention has beendescribed using the embodiment, but the embodiment is simply an example,and the invention can be carried out with a variety of modificationswithin the scope of the purport. In addition, it is needless to say thatthe scope of right of the twelfth aspect of the invention is not limitedto the above embodiment.

Thus far, the specific embodiments according to the twelfth aspect ofthe invention have been described using Embodiment 12-1 and Embodiment12-2, but the twelfth aspect of the invention is not limited to theabove embodiments.

<<The Thirteenth Aspect of the Invention>>

Next, a thermoplastic resin material including a polyamide-basedthermoplastic elastomer and a rubber that constitutes the tire frame inthe thirteenth aspect of the invention, and a resin material as acomponent of the reinforcing cord layer will be described, and,subsequently, a specific embodiment of the tire of the thirteenth aspectof the invention will be described using the drawings.

[Thermoplastic Resin Material]

The tire of the thirteenth aspect of the invention includes a circulartire frame formed of a thermoplastic resin material including at least apolyamide-based thermoplastic elastomer and a rubber.

—Polyamide-Based Thermoplastic Elastomer—

The polyimide-based thermoplastic elastomer is an elastic macromolecularcompound, and refers to a thermoplastic resin material which is made ofa copolymer including a polymer that constitutes a crystalline hardsegment having a high melting point, and a polymer that constitutes anon-crystalline soft segment having a low glass transition temperature,and which has an amide bond (—CONH—) in the main chain of the polymerthat constitutes the hard segment. As the “polyamide-based thermoplasticelastomer” in the present embodiment, the same polyamide-basedthermoplastic elastomer as in the above first aspect of the inventioncan be used.

—Rubber—

The “rubber” is an elastic macromolecular compound.

As described above, the rubber is distinguished from the thermoplasticelastomer which is a thermoplastic resin material made of a copolymerincluding a polymer that constitutes a crystalline hard segment having ahigh melting point, and a polymer that constitutes a non-crystallinesoft segment having a low glass transition temperature.

The rubber is not particularly limited, and examples thereof includenatural rubber (NR), isoprene rubber (IR), butadiene rubber (BR),styrene-butadiene copolymer rubber (SBR), acrylonitrile-butadienecopolymer rubber (NBR), chloroprene rubber (CR), butyl rubber (IIR),halogenated butyl rubber (Br—IIR, Cl—IIR, and the like),ethylene-propylene-diene rubber (EPDM), and the like. NIR obtained bysubstituting all butadiene in the acrylonitrile-butadiene copolymerrubber with isoprene or NBIR obtained by substituting some of butadienewith isoprene may be used.

Among the above, BR, SBR, NBR, NIR and NBIR are preferable, and BR, SBR,IR and NBR are more preferable from the viewpoint of the easy control ofthe flexibility of the thermoplastic resin material.

From the viewpoint of increasing the elastic modulus of the rubber,fixing the diameter of dispersed rubber particles, and improvingcreeping, vulcanized rubber obtained by vulcanizing rubber may be usedas the rubber. Rubber may be vulcanized using a known method, andexamples of the method include the methods described in JP-A No.11-048264, JP-A No. 11-029658, JP-A No. 2003-238744, and the like. Therubber is preferably grinded for miniaturization and injected whenblended with the polyamide-based thermoplastic elastomer. It isparticularly preferable to use dynamic crosslinking in which the rubberis dispersed and crosslinked (vulcanized) while kneading thepolyamide-based thermoplastic elastomer and the rubber.

The rubber may be vulcanized by, for example, arbitrarily mixing areinforcing material, such as carbon black, a filler, a vulcanizingagent, a vulcanization accelerator, a fatty acid or a salt thereof, ametallic oxide, a process oil, an age inhibitor, and the like with therubber, kneading the components using a Banbury mixer, and then heatingthe components at 120° C. to 235° C.

As the vulcanizing agent, a known vulcanizing agent, for example,sulfur, an organic peroxide, a resin vulcanizing agent, or the like isused.

As the vulcanization accelerator, a known vulcanization accelerator, forexample, aldehyde, ammonia, amine, guanidine, thiourea, thiasol,sulfenamide, thiuram, dithiocarbamate, xanthate, or the like is used.

Examples of the fatty acid include stearic acid, palmitic acid, myristicacid, lauric acid and the like, and the above may be blended in a saltstate, such as zinc stearate. Among the above, a stearic acid ispreferable.

In addition, examples of the metallic oxide include zinc oxide (ZnO),iron oxide, magnesium oxide, and the like, and, among the above, zincoxide is preferable.

As the process oil, any of aromatic-based, naphthene-based, andparaffin-based process oil may be used.

Examples of the age inhibitor include an amine-ketone-based inhibitor,an imidazole-based inhibitor, an amine-based inhibitor, a phenol-basedinhibitor, a sulfur-based inhibitor, a phosphorous-based inhibitor andthe like.

The mass ratio (x:y) between the polyamide-based thermoplastic elastomer(x) and the rubber (y) in the thermoplastic resin [when thethermoplastic resin includes a thermoplastic elastomer other than thepolyamide-based thermoplastic elastomer, the mass ratio (x:y′) betweenthe polyamide-based thermoplastic elastomer (x) and the total amount(y′) of the rubber and the thermoplastic elastomer other than thepolyamide-based thermoplastic elastomer] is preferably from 95:5 to50:50. When the mass ratio between these elastomers is from 95:5 to50:50, the polyamide-based thermoplastic elastomer and the rubber canhave the characteristics of the rubber while maintaining thecharacteristics of the polyamide-based thermoplastic elastomer so thatthe elastic modulus of the tire can be easily controlled whilemaintaining the weldability between the reinforcing cord member and thetire frame through the polyamide-based thermoplastic elastomer, wherebythe durability of the tire is further improved. The (x:y) and the (x:y′)are both more preferably from 90:10 to 50:50.

—Thermoplastic Elastomer Having a High Affinity for Rubber—

The thermoplastic resin material may include a thermoplastic elastomerhaving a high affinity for rubber. Hereinafter, the thermoplasticelastomer having a high affinity for rubber will also be called the“rubber affinity thermoplastic elastomer”.

When the thermoplastic resin material further includes the rubberaffinity thermoplastic elastomer, it is possible to finely disperse therubber in the thermoplastic resin material. Furthermore, it isconsidered that, due to the interaction between the polyamide-basedthermoplastic elastomer and the acid-modified portion, the tensilestrength is improved, ductile fracture occurs even in the case offracturing, and brittle fracture or lamellar fracture is not easilycaused. The occurrence of ductile fracture, brittle fracture andlamellar fracture can be checked by visually observing the fracturedsurface of the thermoplastic resin material.

Here, the “high affinity for rubber” refers to a state in which themolecular skeleton of the rubber and the molecular skeleton of thethermoplastic elastomer are similar so that the rubber is incorporatedinto the dispersed particles of the thermoplastic elastomer or thethermoplastic elastomer is incorporated into the dispersed particles ofthe rubber when the thermoplastic elastomer is mixed together with therubber.

However, not all the thermoplastic elastomer and the rubber in thethermoplastic resin material need to be in the above state, and thethermoplastic elastomer and the rubber in the thermoplastic resinmaterial may be partially in the above state.

For example, when the skeleton that constitutes the main chain of thepolymer that constitutes the hard segment or the soft segment in thethermoplastic elastomer is similar to the skeleton that constitutes themain chain of the rubber molecules, the thermoplastic elastomer and therubber are considered to have high affinities for each other.Specifically, with respect to styrene-butadiene copolymer rubber (SBR),examples of the rubber affinity thermoplastic elastomer include apolystyrene-based thermoplastic elastomer (particularly SEBS). Inaddition, with respect to butadiene rubber (BR) andethylene-propylene-diene rubber (EPDM), examples of the rubber affinitythermoplastic elastomer include a polyolefin-based thermoplasticelastomer.

In addition, the rubber affinity thermoplastic elastomer is preferablyan acid-modified thermoplastic elastomer in which an acid group (forexample, a carboxy group) is introduced into some of the thermoplasticelastomer particles. When the rubber affinity thermoplastic elastomer isacid-modified, it is possible to further improve the fine dispersion ofthe rubber due to the interaction between the polyamide-basedthermoplastic elastomer and the acid-modified portions in thethermoplastic resin material.

The rubber affinity thermoplastic elastomer is not particularly limitedas long as it is a thermoplastic elastomer other than thepolyamide-based thermoplastic elastomer and has a high affinity for therubber, and examples thereof include polyolefin-based thermoplasticelastomers, polystyrene-based thermoplastic elastomers, polyester-basedthermoplastic elastomers, polyurethane-based thermoplastic elastomersand the like. Polyolefin-based thermoplastic elastomers andstyrene-based thermoplastic thermoplastic elastomers are preferable.

Next, polyolefin-based thermoplastic elastomers, polystyrene-basedthermoplastic elastomers, polyester-based thermoplastic elastomers, andpolyurethane-based thermoplastic elastomers, which can constitute therubber affinity thermoplastic elastomer, will be described.

(Polyolefin-Based Thermoplastic Elastomer)

The “polyolefin-based thermoplastic elastomer” is an elasticmacromolecular compound, and refers to a thermoplastic resin materialmade of a copolymer including a polymer that constitutes a crystallinehard segment having a high melting point, and a polymer that constitutesa non-crystalline soft segment having a low glass transitiontemperature, in which the polymer that constitutes the hard segment is apolyolefin, such as polypropylene or polyethylene. The “polyolefin-basedthermoplastic elastomer” in the present embodiment is the same as in theabove second aspect of the invention.

(Polystyrene-Based Thermoplastic Elastomer)

The polystyrene-based thermoplastic elastomer is an elasticmacromolecular compound, and refers to a thermoplastic resin materialmade of a copolymer including a polymer that constitutes the hardsegment, and a polymer that constitutes a non-crystalline soft segmenthaving a low glass transition temperature, in which the polymer thatconstitutes the hard segment includes polystyrene. The“polystyrene-based thermoplastic elastomer” in the present embodiment isthe same as in the above second aspect of the invention.

(Polyester-Based Thermoplastic Elastomer)

The polyester-based thermoplastic elastomer in the thirteenth aspect ofthe invention is an elastic macromolecular compound, and refers to athermoplastic resin material made of a copolymer including a polymerthat constitutes a crystalline hard segment having a high melting point,and a polymer that constitutes a non-crystalline soft segment having alow glass transition temperature, in which the polymer that constitutesthe hard segment includes a polyethylene resin. The “polyester-basedthermoplastic elastomer” in the present embodiment is the same as in theabove second aspect of the invention.

(Polyurethane-Based Thermoplastic Elastomer)

Examples of the polyurethane-based thermoplastic elastomer include amaterial in which at least a polyurethane constitutes a hard segmentforming a pseudo crosslink through physical aggregation, and anotherpolymer constitutes the non-crystalline soft segment having a low glasstransition temperature. The “polyurethane-based thermoplastic elastomer”in the present embodiment is the same as in the above second aspect ofinvention.

The mass ratio (z:y) between the rubber affinity thermoplastic elastomer(z) and the rubber (y) in the thermoplastic resin material according tothe thirteenth aspect of the invention is preferably from 95:5 to 0:100,and more preferably from 90:10 to 0:100.

In addition, the total content of the polyamide-based thermoplasticelastomer and the rubber (the polyamide-based thermoplastic elastomer,the rubber and the rubber affinity thermoplastic elastomer when thethermoplastic resin material includes the rubber affinity thermoplasticelastomer) in the thermoplastic resin material is not particularlylimited, but is preferably 50 mass % to 100 mass % with respect to thetotal amount of the thermoplastic resin material. When the total contentis 50 mass % or more with respect to the total amount of thethermoplastic resin material, it is possible to sufficiently develop thecharacteristics of the thermoplastic resin material.

The thermoplastic resin material may contain a thermoplastic elastomerother than the polyamide-based thermoplastic elastomer, a thermoplasticresin, a variety of fillers (for example, silica, calcium carbonate andclay) and a variety of additives, such as an age inhibitor, oil, aplasticizer, a coloring agent, a weather-resisting agent and areinforcing material, as desired.

In order to obtain the thermoplastic resin material, the polyamide-basedthermoplastic elastomer, the rubber, the rubber affinity thermoplasticelastomer as necessary, the additives, and the like, which are describedabove, may be mixed so as to obtain the above amount ratio, and kneaded.

The mixing and kneading of the respective components can be carried outusing a LABOPLASTOMILL 50MR biaxial extruder manufactured by Toyo SeikiSeisaku-sho, Ltd.

Finely grinded vulcanized rubber may be injected into the biaxialextruder, or the rubber may be vulcanized while kneading a vulcanizingagent and the like with the rubber using a Banbury or the like, and thenkneading with the thermoplastic elastomer in the biaxial extruder. Therubber is preferably vulcanized while kneading the rubber with thethermoplastic elastomer in the biaxial extruder.

—The Characteristics of the Thermoplastic Resin Material—

The tensile modulus of elasticity, which is defined in JIS K7113:1995,of the thermoplastic resin material according to the thirteenth aspectof the invention is preferably 100 MPa to 1000 MPa, more preferably 100MPa to 800 MPa, and particularly preferably 100 MPa to 700 MPa. When thetensile modulus of elasticity of the thermoplastic resin material is 100MPa to 1000 MPa, fitting onto a rim can be efficiently carried out whileholding the shape of the tire frame.

The tensile yield strength, which is defined in JIS K7113:1995, of thethermoplastic resin material according to the thirteenth aspect of theinvention is preferably 5 MPa or more, preferably 5 MPa to 20 MPa, andstill more preferably 5 MPa to 17 MPa. When the tensile yield strengthof the thermoplastic resin material is 5 MPa or more, it is possible towithstand deformation caused by a load applied to the tire at the timeof driving or the like.

The tensile yield elongation, which is defined in JIS K7113:1995, of thethermoplastic resin material according to the thirteenth aspect of theinvention is preferably 10% or more, preferably 10% to 70%, and stillmore preferably 15% to 60%. When the tensile yield elongation of thethermoplastic resin material is 10% or more, it is possible to increasethe elastic region and improve the fittability onto a rim.

The tensile elongation at break, which is defined in JIS K7113:1995, ofthe thermoplastic resin material according to the thirteenth aspect ofthe invention is preferably 50% or more, preferably 100% or more, stillmore preferably 150% or more, and particularly preferably 200% or more.When the tensile elongation at break of the resin material is 50% ormore, it is possible to improve the fittability onto a rim and avoidfracture due to collision.

The deflection temperature under load (under a load of 0.45 MPa), whichis defined in ISO75-2 or ASTM D648, of the thermoplastic resin materialaccording to the thirteenth aspect of the invention is preferably 50° C.or more, preferably 50° C. to 150° C., and still more preferably 50° C.to 130° C. When the deflection temperature under load of thethermoplastic resin material is 50° C. or more, it is possible tosuppress deformation of a tire frame even when vulcanization is carriedout in the production of a tire.

[The Resin Material as a Component of the Reinforcing Cord Layer]

The tire of the thirteenth aspect of the invention may have thereinforcing cord member which is wound around the outer circumference ofthe tire frame in the circumferential direction so as to form thereinforcing cord layer.

The “resin material as a component of the reinforcing cord layer”according to the thirteenth aspect of the invention is the same as the[resin material as a component of the reinforcing cord layer] accordingto the first aspect of the invention.

Embodiment 13-1

Hereinafter, a tire according to Embodiment 13-1 of the tire of thethirteenth aspect of the invention will be described according to thedrawings.

Here, the tire according to Embodiment 13-1 is the same as the aboveEmbodiment 13 except for the following points. Therefore, the samereference numerals and drawings will be used in the descriptionregarding the same drawings and members.

The tire case 17 of the present embodiment is formed of a thermoplasticresin material including a polyamide-based thermoplastic elastomer(“UBESTA XPA9055X1” manufactured by Ube Industries, Ltd.) and butadienerubber (BR) at a mass ratio of 70:30. In the present embodiment, thetire case 17 is formed of the thermoplastic resin material according tothe thirteenth aspect of the invention alone, but the thirteenth aspectof the invention is not limited to this configuration, and, similarly toan ordinary pneumatic rubber tire of the related art, otherthermoplastic resin materials having different characteristics may beused in the respective portions (the side portions 14, the crown portion16, the bead portions 12, and the like) of the tire case 17. Otherpoints are the same as in the tire according to the above Embodiment 13,and the manufacturing method is also the same.

(Effects)

In the tire 10 of the present embodiment, since the tire case 17 isformed of the thermoplastic resin material including a polyamide-basedthermoplastic elastomer (“UBESTA XPA9055X1” manufactured by UbeIndustries, Ltd.) and butadiene rubber (BR) at a mass ratio of 70:30,the impact resistance, tensile modulus of elasticity and tensilestrength are excellent. Therefore, the tire 10 of the present embodimentis excellent in terms of durability. Furthermore, since the weight islight compared to rubber of the related art, it is possible to decreasethe tan δ. Therefore, since the weight of the tire 10 of the presentembodiment can be decreased, and the rolling resistance is alsosuppressed, it is possible to improve the fuel consumption of anautomobile in which the tire is used.

In addition, the polyamide-based thermoplastic elastomer, which is oneof the components of the thermoplastic resin material, has high adhesionproperties to the reinforcing cord 26, and, furthermore, is excellent interms of fixing performances, such as weld strength. Therefore, it ispossible to suppress the phenomenon in which air remains around thereinforcing cord 26 in the reinforcing cord winding process(incorporation of air). When the adhesion properties and weldability tothe reinforcing cord 26 are high, and, furthermore, incorporation of airinto the periphery of the reinforcing cord member is suppressed, it ispossible to effectively suppress the movement of the reinforcing cord 26caused by a force applied thereto at the time of driving or the like.Thereby, for example, even when a tire-constituting member has beenprovided so as to cover the entirety of the reinforcing cord member onthe outer circumference of the tire frame, since the movement of thereinforcing cord member is suppressed, the separation or the like of themembers (including the tire frame) is suppressed, and the durability ofthe tire 10 is improved.

In addition, in the tire 10 of the present embodiment, since thereinforcing cord 26 having a higher stiffness than the thermoplasticresin material is helically wound in the circumferential direction onthe outer circumferential surface of the crown portion 16 in the tirecase 17 formed of the thermoplastic resin material, the punctureresistance, the cutting resistance and the stiffness of the tire 10 inthe circumferential direction are improved. Meanwhile, the improvementof the stiffness of the tire 10 in the circumferential directionprevents the creeping in the tire case 17 formed of the thermoplasticresin material.

In addition, in the cross-sectional view of the tire case 17 along theaxial direction (the cross section illustrated in FIG. 1), since atleast a portion of the reinforcing cord 26 is embedded in the outercircumferential surface of the crown portion 16 in the tire case 17formed of the thermoplastic resin material, and is adhered to thethermoplastic resin material, incorporation of air during manufacturingis suppressed, and the movement of the reinforcing cord 26 caused by aforce applied thereto at the time of driving or the like is suppressed.Thereby, the separation or the like of the reinforcing cord 26, the tirecase 17 and the tread 30 is suppressed, and the durability of the tire10 is improved.

In addition, since the depth L of embedding of the reinforcing cord 26is ⅕ or more of the diameter D as illustrated in FIG. 2, incorporationof air during manufacturing is effectively suppressed, and the movementof the reinforcing cord 26 caused by a force applied thereto at the timeof driving or the like is further suppressed.

When the reinforcing cord layer 28 is configured to include thethermoplastic resin material as described above, since it is possible todecrease the difference in hardness between the tire case 17 and thereinforcing cord layer 28 compared to the case when the reinforcing cord26 is fixed using cushion rubber, the reinforcing cord 26 can be furtheradhered and fixed to the tire case 17. Thereby, the above incorporationof air can be effectively prevented, and it is possible to effectivelysuppress the movement of the reinforcing cord member at the time ofdriving.

Furthermore, when the reinforcing cord member is a steel cord, since thereinforcing cord 26 can be easily separated and collected from thethermoplastic resin material through heating when disposing of the tire,it is advantageous in terms of the recycling properties of the tire 10.In addition, the resin material generally has a low loss factor (Tan δ)compared to vulcanized rubber. Therefore, when the reinforcing cordlayer includes a large amount of the resin material, it is possible toimprove the rolling properties of the tire. Furthermore, the resinmaterial having a relatively high elastic modulus compared to vulcanizedrubber is advantageous in that the in-plane shear stiffness is large,and steering stability and abrasion resistance during driving with thetire are also excellent.

In addition, since the tread 30 that comes into contact with roadsurfaces is made of a rubber material that is more abrasion-resistantthan the thermoplastic resin material, the abrasion resistance of thetire 10 is improved.

Furthermore, since an annular bead core 18 made of a metallic materialis embedded in the bead portion 12, the tire case 17, that is, the tire10 is strongly held to the rim 20 similarly to a pneumatic rubber tireof the related art.

In addition, furthermore, since the sealing layer 24 made of a rubbermaterial having higher sealing properties than the thermoplastic resinmaterial is provided in a portion, which comes into contact with the rim20, of the bead portion 12, the sealing properties between the tire 10and the rim 20 are improved. Therefore, compared to the case whensealing is carried out between the rim 20 and the thermoplastic resinmaterial, the air leakage from the tire is further suppressed. Inaddition, the rim fitting properties are also improved when the sealinglayer 24 is provided.

The above embodiment employs a configuration in which the reinforcingcord 26 is heated, and the thermoplastic resin material in the portionwith which the heated reinforcing cord 26 comes into contact is meltedor softened, but the thirteenth aspect of the invention is not limitedto this configuration, and the reinforcing cord 26 may be embedded inthe crown portion 16 after heating the outer circumferential surface ofthe crown portion 16, in which the reinforcing cord 26 is to beembedded, using a hot air generating apparatus without heating thereinforcing cord 26.

In addition, in Embodiment 13-1, a heater and a fan are used as the heatsource of a cord heating device 59, but the thirteenth aspect of theinvention is not limited to this configuration, and a configuration inwhich the reinforcing cord 26 is directly heated using radiation heat(for example, infrared rays or the like) may be employed.

Furthermore, Embodiment 13-1 employs a configuration in which theportion, in which the thermoplastic resin material having thereinforcing cord 26 embedded therein is melted or softened, is forciblycooled using the second metal roller 64, but the thirteenth aspect ofthe invention is not limited to this configuration, and a configurationin which the portion, in which the thermoplastic resin material ismelted or softened, is forcibly cooled and solidified by directlyblowing cold air to the portion in which the thermoplastic resinmaterial is melted or softened may be employed.

In addition, Embodiment 13-1 employs a configuration in which thereinforcing cord 26 is heated; however, for example, a configuration inwhich the outer circumference of the reinforcing cord 26 is coated withthe same thermoplastic resin material as the tire case 17 may beemployed, and, in this case, it is possible to effectively suppressincorporation of air during embedding in the crown portion 16 by heatingthe reinforcing cord 26 and the coating of the thermoplastic resinmaterial when winding the coated reinforcing cord around the crownportion 16 of the tire case 17.

In addition, the helical winding of the reinforcing cord 26 is easy inthe manufacturing, but a method, in which the reinforcing cord 26 isformed to be discontinuous in the width direction, or the like can bealso considered.

The tire 10 of Embodiment 13-1 is a so-called tubeless tire in which anair chamber is formed between the tire 10 and the rim 20 by mounting thebead portion 12 on the rim 20, but the thirteenth aspect of theinvention is not limited to this configuration, and the tire may have acomplete tube shape.

Thus far, an embodiment of the thirteenth aspect of the invention hasbeen described using the embodiment, but the embodiment is simply anexample, and the invention can be carried out with a variety ofmodifications within the scope of the purport. In addition, it isneedless to say that the scope of right of the thirteenth aspect of theinvention is not limited to the above embodiment.

Embodiment 13-2

Next, the tire and the method of manufacturing the tire of thethirteenth aspect of the invention according to Embodiment 13-2 will bedescribed according to the drawings. Similarly to the above Embodiment13-1, the tire of the present embodiment exhibits substantially the samecross-sectional shape as an ordinary pneumatic rubber tire of therelated art. Here, the tire according to Embodiment 13-2 is the same asthe above Embodiment 13 except for the following points. Therefore, thesame reference numerals and drawings will be used in the descriptionregarding the same drawings and members.

In the tire of Embodiment 13-2, similarly to the above Embodiment 13-1,the tire case 17 is formed of a thermoplastic resin material including apolyamide-based thermoplastic elastomer (“UBESTA XPA9055X1” manufacturedby Ube Industries, Ltd.) and butadiene rubber (BR) at a mass ratio of70:30. Other points are the same as in the tire according to the aboveEmbodiment 13, and the manufacturing method is also the same.

In addition, the elastic modulus of a resin material for coating 27 ispreferably set in a range of 0.1 times to 10 times the elastic modulusof a resin material that forms the tire case 17. When the elasticmodulus of the resin material for coating 27 is 10 times or less theelastic modulus of the thermoplastic resin material that forms the tirecase 17, the crown portion does not become too hard, and fitting onto arim can be easily carried out. In addition, when the elastic modulus ofthe resin material for coating 27 is 0.1 times or more the elasticmodulus of the thermoplastic resin material that forms the tire case 17,the resin that constitutes the reinforcing cord layer 28 does not becometoo soft, and the belt in-plane shear stiffness is excellent and thecornering force is improved. Meanwhile, in the present embodiment, asthe resin material for coating 27, the same material as thethermoplastic resin material (in the present embodiment, a thermoplasticresin material including a polyamide-based thermoplastic elastomer(“UBESTA XPA9055X1” manufactured by Ube Industries, Ltd.) and butadienerubber (BR) at a mass ratio of 70:30) is used.

(Effects)

In the tire 200 of the present embodiment, since the tire case 17 isformed of the thermoplastic resin material including the polyamide-basedthermoplastic elastomer and the rubber at a mass ratio of 70:30, theimpact resistance is excellent, and, furthermore, the tensile modulus ofelasticity and tensile strength are also excellent. Therefore, the tire10 of the present embodiment is excellent in terms of durability.Furthermore, since the weight is light compared to rubber of the relatedart, it is possible to decrease the tan δ. Therefore, since the weightof the tire 200 of the present embodiment can be decreased, and therolling resistance is also suppressed, it is possible to improve thefuel consumption of an automobile in which the tire is used.

In addition, when the reinforcing cord layer 28 is configured to includethe coated cord member 26B, since it is possible to decrease thedifference in hardness between the tire case 17 and the reinforcing cordlayer 28 compared to the case when the reinforcing cord 26A is simplyfixed using cushion rubber 29, the coated cord member 26B can be furtheradhered and fixed to the tire case 17. Thereby, the above incorporationof air can be effectively prevented, and it is possible to effectivelysuppress the movement of the reinforcing cord member at the time ofdriving.

Furthermore, when the reinforcing cord member is a steel cord, since thecord member 26A can be easily separated and collected from the coatedcord member 26B through heating when disposing of the tire, it isadvantageous in terms of the recycling properties of the tire 200. Inaddition, the resin material generally has a low loss factor (Tan δ)compared to vulcanized rubber. Therefore, when the reinforcing cordlayer includes a large amount of the resin material, it is possible toimprove the rolling properties of the tire. Furthermore, the resinmaterial having a relatively high elastic modulus compared to vulcanizedrubber is advantageous in that the in-plane shear stiffness is large,and steering stability and abrasion resistance during driving with thetire are also excellent.

In the method of manufacturing the tire of the present embodiment, whenthe tire case 17, the cushion rubber 29 and a tread rubber 30A areintegrated, since the outer circumferential surface 17S of the tire case17 has been subjected to a roughening treatment, the bonding properties(adhesion properties) are improved due to the anchor effect. Inaddition, since the resin material that forms the tire case 17 is dug upby the collision of a blasting abrasive, the wettability of a bondingagent is improved. Thereby, a state in which the bonding agent isuniformly coated on the outer circumferential surface 17S of the tirecase 17 is held, and the bonding strength between the tire case 17 andthe cushion rubber 29 can be ensured.

Particularly, even when protrusions and recesses are formed on the outercircumferential surface 17S of the tire case 17, the peripheries of therecess portions (recess walls and recess bottoms) are subjected to aroughening treatment by making the blasting abrasive collide with therecess portions (voids 28A), and the bonding strength between the tirecase 17 and the cushion rubber 29 can be ensured.

Meanwhile, since the cushion rubber 29 is laminated in theroughening-treated areas on the outer circumferential surface 17S of thetire case 17, the bonding strength between the tire case 17 and thecushion rubber can be effectively ensured.

When the cushion rubber 29 has been vulcanized in a vulcanizing process,the cushion rubber 29 flows into the roughened recesses and protrusionsformed on the outer circumferential surface 17S of the tire case 17through the roughening treatment. In addition, when vulcanization iscompleted, the anchor effect is developed due to the cushion rubber 29that has flowed into the roughened recesses and protrusions so that thebonding strength between the tire case 17 and the cushion rubber 29 isimproved.

The tire 200 manufactured using the above method of manufacturing a tireensures the bonding strength between the tire case 17 and the cushionrubber 29, that is, ensures the bonding strength between the tire case17 and the tread 30 through the cushion rubber 29. Thereby, theseparation between the outer circumferential surface 17S of the tirecase 17 of the tire 200 and the cushion rubber 29 is suppressed at thetime of driving or the like.

In addition, since the outer circumference of the tire case 17 is madeof the reinforcing cord layer 28, the puncture resistance and thecutting resistance are improved compared to a case in which the outercircumference is made of something other than the reinforcing cord layer28.

In addition, since the reinforcing cord layer 28 is formed by windingthe coated cord member 26B, the stiffness of the tire 200 in thecircumferential direction is improved. The improvement of the stiffnessin the circumferential direction suppresses creeping (a phenomenon inwhich the plastic deformation of the tire case 17 increases over timeunder a constant stress) in the tire case 17, and the pressureresistance with respect to the air pressure from the inside in the tireradial direction is improved.

In the present embodiment, the recesses and protrusions are formed onthe outer circumferential surface 17S of the tire case 17, but thethirteenth aspect of the invention is not limited thereto, and aconfiguration in which the outer circumferential surface 17S is formedto be flat may be employed.

In addition, in the tire case 17, the reinforcing cord layer may beformed by covering the coated cord member, which is wound around andbonded to the crown portion of the tire case, with a thermoplasticmaterial for coating. In this case, a coating layer can be formed bydischarging a thermoplastic material for coating in a molten or softenedstate on the reinforcing cord layer 28. In addition, the coating layermay be formed by heating a welding sheet into a molten or softened statewithout using an extruder, and attaching the welding sheet to thesurface (outer circumferential surface) of the reinforcing cord layer28.

The above Embodiment 13-2 employs a configuration in which case dividedparts (tire case half parts 17A) are bonded so as to form the tire case17, but the thirteenth aspect of the invention is not limited thereto,and the tire case 17 may be integrally formed using a mold or the like.

The tire 200 of Embodiment 13-2 is a so-called tubeless tire in which anair chamber is formed between the tire 200 and the rim 20 by mountingthe bead portion 12 on the rim 20, but the thirteenth aspect of theinvention is not limited to this configuration, and the tire 200 mayhave, for example, a complete tube shape.

In Embodiment 13-2, the cushion rubber 29 is disposed between the tirecase 17 and the tread 30, but the thirteenth aspect of the invention isnot limited thereto, and a configuration in which the cushion rubber 29is not disposed may be employed.

In addition, Embodiment 13-2 employs a configuration in which the coatedcord member 26B is helically wound around the crown portion 16, but thethirteenth aspect of the invention is not limited thereto, and aconfiguration in which the coated cord member 26B is wound to bediscontinuous in the width direction may be employed.

Embodiment 13-2 employs a configuration in which a thermoplasticmaterial is used as the resin material for coating 27 that forms thecoated cord member 26B, and the resin material for coating 27 is heatedinto a molten or softened state so as to weld the coated cord member 26Bon the outer circumferential surface of the crown portion 16, but thethirteenth aspect of the invention is not limited to this configuration,and a configuration in which the coated cord member 26B is adhered tothe outer circumferential surface of the crown portion 16 using anadhesive or the like without heating the resin material for coating 27may be employed.

In addition, a configuration in which a thermosetting resin is used asthe resin material for coating 27 that forms the coated cord member 26B,and the coated cord member 26B is adhered to the outer circumferentialsurface of the crown portion 16 using an adhesive or the like withoutheating may be employed.

Furthermore, a configuration in which a thermosetting resin is used asthe resin material for coating 27 that forms the coated cord member 26B,and the tire case 17 is formed of a thermoplastic resin material may beemployed. In this case, the coated cord member 26B may be adhered to theouter circumferential surface of the crown portion 16 using an adhesiveor the like, or the coated cord member 26B may be welded on the outercircumferential surface of the crown portion 16 by heating the portion,which is to be provided with the coated cord member 26B, of the tirecase 17 into a molten or softened state.

In addition, furthermore, a configuration in which a thermoplasticmaterial is used as the resin material for coating 27 that forms thecoated cord member 26B, and the tire case 17 is formed of athermoplastic resin material may be employed. In this case, the coatedcord member 26B may be adhered to the outer circumferential surface ofthe crown portion 16 using an adhesive or the like, or the coated cordmember 26B may be welded on the outer circumferential surface of thecrown portion 16 by heating the portion, which is to be provided withthe coated cord member 26B, of the tire case 17 into a molten orsoftened state, and heating the resin material for coating 27 into amolten or softened state. Meanwhile, when both the tire case 17 and thecoated cord member 26B have been heated into a molten or softened state,since both are well mixed, the bonding strength is improved. Inaddition, when thermoplastic resin materials are used as both the resinmaterial that forms the tire case 17 and the resin material for coating27 that forms the coated cord member 26B, the thermoplastic resinmaterials are preferably the same kind of thermoplastic materials,particularly, the same thermoplastic material.

In addition, furthermore, an adhesive may be coated on the outercircumferential surface 17S of the tire case 17, after the surface ofthe outer circumferential surface 17S, on which the roughening treatmenthas been carried out, is activated using a corona treatment, a plasmatreatment or the like so as to increase the hydrophilicity.

In addition, furthermore, the order for manufacturing the tire 200 isnot limited to the order in Embodiment 13-2, and may be appropriatelychanged.

Thus far, an embodiment of the thirteenth aspect of the invention hasbeen described using the embodiment, but the embodiment is simply anexample, and the invention can be carried out with a variety ofmodifications within the scope of the purport. In addition, it isneedless to say that the scope of right of the thirteenth aspect of theinvention is not limited to the above embodiment.

Thus far, the specific embodiments according to the thirteenth aspect ofthe invention have been described using Embodiment 13-1 and Embodiment13-2, but the thirteenth aspect of the invention is not limited to theabove embodiments.

The tire of the first aspect of the invention may be configured asfollows: as described in Embodiment 1-1.

(1-1-1) The tire of the first aspect of the invention may be configuredso that at least a part of the reinforcing cord member is embedded inthe outer circumference of the tire frame formed of the thermoplasticresin material in the cross-sectional view along the axial direction ofthe tire frame.

When a part of the reinforcing cord member is embedded in the outercircumference of the tire frame as such, a phenomenon in which airremains in the area around the cord during winding of the reinforcingcord member (incorporation of air) may further be suppressed. Whenincorporation of air into the area around the reinforcing cord member issuppressed, movement of the reinforcing cord member due to, for example,a force applied during running is suppressed. Accordingly, for example,in the case where the tire-constituting member is provided on the outercircumference of the tire frame to cover the entire reinforcing cordmember, since the movement of the reinforcing cord member is suppressed,an occurrence of peeling and the like between the members (including thetire frame) is suppressed. Accordingly, durability is enhanced.

(1-1-2) The tire of the first aspect of the invention may be providedwith a tread formed of a material having higher wear resistance than thethermoplastic resin material on the outer side in the radial directionof the reinforcing cord layer.

By having a configuration in which the tread that comes into contactwith the road surface is formed of the material having higher wearresistance than the thermoplastic resin material as such, the wearresistance of the tire may further be enhanced.

(1-1-3) In the tire of the first aspect of the invention, ⅕ or more ofthe diameter of the reinforcing cord member may be embedded in the outercircumference of the tire frame along the circumferential direction inthe cross-sectional view along the axial direction of the tire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord membermay be effectively suppressed, and thus movement of the reinforcing cordmember due to, for example, a force applied during running may furtherbe suppressed.

(1-1-4) The tire of the first aspect of the invention may be configuredso that the tire frame includes, on the inner side in the radialdirection, a bead portion that comes into contact with a bead seat and arim flange of a rim, and an annular bead core formed of a metal materialis embedded in the bead portion.

By providing the bead portion which is a part for fitting onto the rimin the tire frame, and moreover, by embedding the annular bead core madeof the metal material in the bead portion as such, the tire frame (thatis, tire) may be firmly held on the rim, similarly to conventionalpneumatic tires made of rubber.

(1-1-5) The tire of the first aspect of the invention may be providedwith a sealing portion made of a material having higher sealingproperties (adhesion to the rim) than the thermoplastic resin material,in a part where the bead portion comes into contact with the rim.

By providing the seal portion made of the material having higher sealingproperties than the thermoplastic resin material in the part where thetire frame and the rim come into contact with each other as such,adhesion between the tire (the tire frame) and the rim may be enhanced.Accordingly, compared to a case where only the rim and the thermoplasticresin material are used, leakage of air in the tire may further besuppressed. In addition, by providing the sealing portion, fitting ontothe rim of the tire may be enhanced.

(1-1-6) The tire of the first aspect of the invention may bemanufactured according to the manufacturing method that includes: a tireframe piece forming step of forming a tire frame piece for constitutinga portion of the circular tire frame, using a thermoplastic resinmaterial including at least a polyamide-based thermoplastic elastomer; atire frame piece bonding step of forming the tire frame by fusing two ormore of the tire frame pieces, which make a pair, by applying heat tothe bonding surfaces of the tire frame pieces; and a reinforcing cordmember winding step of winding the reinforcing cord member around theouter circumference of the tire frame in the circumferential directionto form a reinforcing cord layer.

In the manufacturing method, the tire frame pieces of the circular tireframe may be formed of the thermoplastic resin material including thepolyamide-based thermoplastic elastomer. The melting point of thepolyamide-based thermoplastic elastomer may be set to about 100° C. to250° C., and thus the fusing step of the tire frame pieces needs not tobe performed at, for example, a temperature equal to or higher than 300°C. and the fusing step may be performed at a relatively low temperature.Since the fusing step is able to be performed at the relatively lowtemperature as such, productivity of the tire may be enhanced in termsof energy utilization rate and the like. In addition, when the tireframe pieces in which the polyamide-based thermoplastic elastomer isused are fused to form the tire frame, the bonding strength between thetire frame pieces is sufficient, and the performance of the frame itselfis not deteriorated due to the temperature during fusing. Therefore,durability at the time of driving such as puncture resistance and wearresistance of the manufactured tire may be enhanced.

(1-1-7) The manufacturing method of the tire may be configured so that,in the tire frame piece bonding step, the bonding surface of the tireframe piece is heated to a temperature equal to or higher than themelting point (for example, the melting point +10° C. to +150° C.) ofthe thermoplastic resin material that forms the tire frame piece.

When the bonding surface of the divided body is heated to a temperatureequal to or higher than the melting point of the thermoplastic resinmaterial that forms the tire frame piece as such, fusing between thetire frame pieces may be sufficiently performed. Therefore, productivityof the tire may be enhanced while enhancing durability of the tire.

(1-1-8) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, the reinforcing cord memberis wound around the outer circumference of the tire frame in a mannersuch that at least a part of the reinforcing cord member is embeddedwhile melting or softening the outer circumference of the tire frameformed in the tire frame piece bonding step.

By winding the reinforcing cord member around the outer circumference ina manner such that at least a part of the reinforcing cord member isembedded in the outer circumference of the tire frame while melting orsoftening the outer circumference of the tire frame as such, the atleast a part of the reinforcing cord member which is embedded and themelted or softened thermoplastic resin material may be welded.Accordingly, incorporation of air between the outer circumference of thetire frame and the reinforcing cord member in the cross-sectional viewalong the axial direction of the tire frame may further be suppressed.In addition, when the part in which the reinforcing cord member isembedded is cooled and solidified, the fixed condition of thereinforcing cord member embedded in the tire frame is enhanced.

(1-1-9) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, ⅕ or more of the diameterof the reinforcing cord may be embedded in the outer circumference ofthe tire frame in the cross-sectional view along the axial direction ofthe tire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord duringmanufacturing may be effectively suppressed, and moreover, the embeddedreinforcing cord member may become less likely to be caused to come outof the tire frame.

(1-1-10) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, the heated reinforcing cordmember is embedded in the tire frame.

By embedding the reinforcing cord member in the tire frame while heatingthe reinforcing cord member in the reinforcing cord winding step assuch, when the heated reinforcing cord member comes into contact withthe outer circumference of the tire frame, the contact part is melted orsoftened. Therefore, it becomes easy to embed the reinforcing cordmember in the outer circumference of the tire frame.

(1-1-11) The manufacturing method of the tire may be configured so that,in the cord member winding step, the part of the outer circumference ofthe tire frame for embedding the reinforcing cord member is heated.

By heating the part of the outer circumference of the tire frame forembedding the reinforcing cord member as such, the heated part of thetire frame is melted or softened. Therefore, it becomes easy to embedthe reinforcing cord member.

(1-1-12) The manufacturing method of the tire may be configured so that,in the cord member winding step, the reinforcing cord member is wound ina spiral shape in the circumferential direction of the outercircumference of the tire frame while pressing the reinforcing cordmember against the outer circumference of the tire frame.

When the reinforcing cord member is wound in the spiral shape whilepressing the reinforcing cord member against the outer circumference ofthe tire frame as such, the depth of embedding the reinforcing cordmember in the outer circumference of the tire frame may be adjusted.

(1-1-13) The manufacturing method may be configured so that, in the cordmember winding step, after winding the reinforcing cord member aroundthe tire frame, the melted or softened part of the outer circumferenceof the tire frame is cooled.

By forcibly cooling the melted or softened part of the outercircumference of the tire frame after embedding the reinforcing cordmember as such, the melted or softened part of the outer circumferenceof the tire frame may be more quickly and rapidly cooled and solidifiedthan natural cooling. By cooling the outer circumference of the tiremore quickly than natural cooling, deformation of the outercircumference of the tire frame may be suppressed, and movement of thereinforcing cord member may be suppressed.

The tire of the first aspect of the invention may be configured asfollows as described in Embodiment 1-2.

(1-2-1) The tire of the first aspect of the invention may be configuredsuch that the manufacturing method further includes: the rougheningtreatment step of performing the roughening treatment on the outercircumferential surface of the tire frame by allowing a particle-shapedblasting abrasive to collide with the outer circumferential surface ofthe tire frame; and a superposing step of superposing atire-constituting rubber member on the outer circumferential surfacewhich has been subjected to the roughening treatment, via a bondingagent.

When the roughening treatment step is provided as such, theparticle-shaped blasting abrasive collides with the outercircumferential surface of the circular tire frame formed using thethermoplastic resin material that includes the polyamide-basedthermoplastic elastomer, and thus minute roughened unevenness is formedon the outer circumferential surface. The treatment of forming minuteroughened unevenness by allowing the blasting abrasive to collide withthe outer circumferential surface of the tire frame is referred to as aroughening treatment. Thereafter, the tire-constituting rubber member issuperposed on the outer circumferential surface which has been subjectedto the roughening treatment, via the bonding agent. Here, when the tireframe and the tire-constituting rubber member are integrated into eachother, since the outer circumferential surface of the tire frame hasbeen subjected to the roughening treatment, bonding properties(adhesiveness) are enhanced due to the anchor effect. In addition, sincethe resin material that forms the tire frame is ploughed due tocollision of the blasting abrasive, wettability of the outercircumferential surface is enhanced. Accordingly, the outercircumferential surface of the tire frame is held in a state of beinguniformly coated with the bonding agent, and thus the bonding strengthbetween the tire frame and the tire-constituting rubber member may beensured.

(1-2-2) In the tire of the first aspect of the invention, at least apart of the outer circumferential surface of the tire frame may be anuneven portion, and the uneven portion may be subjected to theroughening treatment in the roughening treatment step.

Even if at least a part of the outer circumferential surface of the tireframe is the uneven portion as such, by allowing the blasting abrasiveto collide with the uneven portion, the area around a recess (walls atthe recess, the bottom of the recess) is subjected to the rougheningtreatment, and thus the bonding strength between the tire frame and thetire-constituting rubber member may be ensured.

(1-2-3) The tire of the first aspect of the invention may be configuredsuch that the outer circumference of the tire frame is configured tohave a reinforcing layer that constitutes the uneven portion at theouter circumferential surface, and the reinforcing layer may beconfigured such that a coated cord member formed by coating thereinforcing cord with a resin material of the same kind as or differentfrom the resin material for forming a tire frame is wound in thecircumferential direction of the tire frame.

By configuring the outer circumference of the tire frame to have thereinforcing layer formed by winding the coated cord member in thecircumferential direction of the tire frame as such, the rigidity of thetire frame in the circumferential direction may be enhanced.

(1-2-4) In the tire of the first aspect of the invention, athermoplastic resin material may be used as the resin material that is acomponent of the coated cord member.

By using a thermoplastic material having thermoplasticity as the resinmaterial that is a component of the coated cord member as such, comparedto a case of using a thermosetting material as the resin material, thetire is easily manufactured and is easily recycled.

(1-2-5) The tire of the first aspect of the present invention may beconfigured so that, in the roughening treatment step, an area wider thanthe area for superposing the tire-constituting rubber member issubjected to the roughening treatment.

When the area wider than the area for superposing the tire-constitutingrubber member is subjected to the roughening treatment in the rougheningtreatment step, the bonding strength between the tire frame and thetire-constituting rubber member may be reliably ensured.

(1-2-6) The tire of the first aspect of the invention may be configuredso that, in the roughening treatment step, the outer circumferentialsurface is subjected to the roughening treatment to have an arithmeticmean roughness Ra of 0.05 mm or greater.

When the outer circumferential surface of the tire frame is subjected tothe roughening treatment to have an arithmetic mean roughness Ra of 0.05mm or greater in the roughening treatment step as such, in a case where,for example, an unvulcanized or semi-vulcanized tire-constituting rubbermember is superposed on the outer circumferential surface which has beensubjected to the roughening treatment, via the bonding agent, and isvulcanized, rubber of the tire-constituting rubber member may be causedto flow to the bottom of the roughened uneven portion formed by theroughening treatment. When the rubber of the tire-constituting rubbermember flows to the bottom of the roughened uneven portion, a sufficientanchor effect is exhibited between the outer circumferential surface andthe tire-constituting rubber member, and the bonding strength betweenthe tire frame and the tire-constituting rubber member may be enhanced.

(1-2-7) In the tire of the first aspect of the invention, rubber in theunvulcanized or semi-vulcanized state may be used as thetire-constituting rubber member.

In the case where the rubber in the unvulcanized or semi-vulcanizedstate is used as the tire-constituting rubber member as such, the rubberflows to the roughened uneven portion formed on the outercircumferential surface of the tire frame by the roughening treatmentwhen the tire-constituting rubber member is vulcanized. In addition,when vulcanization is completed, the anchor effect is exhibited by the(vulcanized) rubber that has flowed to the roughened uneven portion, andthus the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

“Vulcanized” is referred to as a state in which the degree ofvulcanization has reached the degree needed for a final product, and the“semi-vulcanized state” is referred to as a state in which the degree ofvulcanization is higher than that of the unvulcanized state but has notreached the degree needed for a final product.

(1-2-8) The tire of the first aspect of the invention may be configuredto include: a circular tire frame that is formed using the thermoplasticresin material including a polyamide-based thermoplastic elastomer andhas the outer circumferential surface subjected to the rougheningtreatment by allowing a particle-shaped blasting abrasive to collidewith the outer circumferential surface; and a tire-constituting rubbermember superposed on the outer circumferential surface which has beensubjected to the roughening treatment, via a bonding agent.

When the circular tire frame which has been subjected to the rougheningtreatment is used as such, the bonding strength between the tire frameand the tire-constituting rubber member may be enhanced by the anchoreffect. In addition, since the outer circumferential surface has beensubjected to the roughening treatment, excellent wettability of thebonding agent is provided. Accordingly, the bonding agent is held in thestate of being uniformly applied onto the outer circumferential surfaceof the tire frame, the bonding strength between the tire frame and thetire-constituting rubber member is ensured, and thus peeling between thetire frame and the tire-constituting rubber member may be suppressed.

The tire of the second aspect of the invention may be configured asfollows as described in Embodiment 2-1.

(2-1-1) The tire of the second aspect of the invention may be configuredso that at least a part of the reinforcing cord member is embedded inthe outer circumference of the tire frame formed of the thermoplasticresin material in the cross-sectional view along the axial direction ofthe tire frame.

When a part of the reinforcing cord member is embedded in the outercircumference of the tire frame as such, a phenomenon in which airremains in the portion around the cord during winding of the reinforcingcord member (incorporation of air) may further be suppressed. Whenincorporation of air into the area around the reinforcing cord member issuppressed, movement of the reinforcing cord member due to, for example,a force applied during running is suppressed. Accordingly, for example,in the case where the tire-constituting member is provided on the outercircumference of the tire frame to cover the entire reinforcing cordmember, since the movement of the reinforcing cord member is suppressed,an occurrence of peeling and the like between the members (including thetire frame) is suppressed, and durability is enhanced.

(2-1-2) The tire of the second aspect of the invention may be providedwith a tread formed of a material having higher wear resistance than thethermoplastic resin material on the outer side in the radial directionof the reinforcing cord layer.

By having a configuration in which the tread that comes into contactwith the road surface is formed of the material having higher wearresistance than the thermoplastic resin material as such, the wearresistance of the tire may further be enhanced.

(2-1-3) In the tire of the second aspect of the invention, ⅕ or more ofthe diameter of the reinforcing cord member may be embedded in the outercircumference of the tire frame along the circumferential direction inthe cross-sectional view along the axial direction of the tire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord membermay be effectively suppressed, and thus movement of the reinforcing cordmember due to, for example, a force applied during running may furtherbe suppressed.

(2-1-4) The tire of the second aspect of the invention may be configuredso that the tire frame includes, on the inner side in the radialdirection, a bead portion that comes into contact with a bead seat and arim flange of a rim, and an annular bead core formed of a metal materialis embedded in the bead portion.

By providing the bead portion which is a part for fitting onto the rimin the tire frame, and moreover, by embedding the annular bead coreformed of the metal material in the bead portion as such, the tire frame(that is, tire) may be firmly held on the rim, similarly to conventionalpneumatic tires made of rubber.

(2-1-5) The tire of the second aspect of the invention may be providedwith a sealing portion made of a material having higher sealingproperties (adhesion to the rim) than the thermoplastic resin material,in a part where the bead portion comes into contact with the rim.

By providing the sealing portion made of the material having highersealing properties than the thermoplastic resin material in the partwhere the tire frame and the rim come into contact with each other assuch, adhesion between the tire (the tire frame) and the rim may beenhanced. Accordingly, compared to a case where only the rim and thethermoplastic resin material are used, leakage of air in the tire mayfurther be suppressed. In addition, by providing the sealing portion,fittability onto the rim of the tire may be enhanced.

(2-1-6) The tire of the second aspect of the invention may bemanufactured according to a manufacturing method that includes: a tireframe piece forming step of forming a tire frame piece for constitutinga part of a circular tire frame, using a thermoplastic resin materialincluding at least a polyamide-based thermoplastic elastomer and anotherelastomer; the tire frame piece bonding step of forming the tire frameby fusing two or more tire frame pieces, which form a pair by applyingheat to the bonding surfaces of the tire frame pieces; and a reinforcingcord member winding step of winding a reinforcing cord member around theouter circumference of the tire frame in the circumferential directionto form a reinforcing cord layer.

In the manufacturing method, the tire frame pieces of the circular tireframe may be formed of the thermoplastic resin material including apolyamide-based thermoplastic elastomer and another r elastomer. Themelting point of the thermoplastic resin material may be set to about100° C. to 250° C., and thus the fusing step of the tire frame pieces atneeds not to be performed at, for example, equal to or higher than 300°C., and the fusing step may be performed at a relatively lowtemperature. Since the fusing step is able to be performed at therelatively low temperature as such, deterioration of the resin may beprevented, and productivity of the tire may be enhanced in terms ofenergy utilization rate and the like. In addition, when the tire framepieces in which a polyamide-based thermoplastic elastomer is used arefused to form a tire frame, the bonding strength between the tire framepieces is sufficient, and the performance of the frame itself is notdeteriorated due to the temperature during fusing. Therefore, durabilityat the time of driving such as puncture resistance and wear resistanceof the manufactured tire may be enhanced.

(2-1-7) The manufacturing method may be configured so that, in the tireframe piece bonding step, the bonding surface of the tire frame piece isheated to a temperature equal to or higher than the melting point (forexample, the melting point +10° C. to +150° C.) of the thermoplasticresin material that forms the tire frame piece.

When the bonding surface of the divided body is heated to a temperatureequal to or higher than the melting point of the thermoplastic resinmaterial that forms the tire frame piece as such, fusing between thetire frame pieces may be sufficiently performed. Therefore, productivityof the tire may be enhanced while enhancing durability of the tire.

(2-1-8) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, the reinforcing cord memberis wound around the outer circumference of the tire frame in a mannersuch that at least a part of the reinforcing cord member is embeddedwhile melting or softening the outer circumference of the tire frameformed in the tire frame piece bonding step.

By winding the reinforcing cord member around the outer circumference ofthe tire frame in a manner such that at least a part of the reinforcingmember is embedded in the outer circumference while melting andsoftening the outer circumference of the tire frame as such, the atleast the part of the reinforcing cord member which is embedded and themelted or softened thermoplastic resin material may be welded.Accordingly, incorporation of air between the outer circumference of thetire frame and the reinforcing cord member in the cross-sectional viewalong the axial direction of the tire frame may further be suppressed.In addition, when the part in which the reinforcing cord member isembedded is cooled and solidified, the fixed condition of thereinforcing cord member embedded in the tire frame is enhanced.

(2-1-9) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, ⅕ or more of the diameterof the reinforcing cord may be embedded in the outer circumference ofthe tire frame in the cross-sectional view along the axial direction ofthe tire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord duringmanufacturing may be effectively suppressed, and moreover, the embeddedreinforcing cord member may become less likely to be caused to come outof the tire frame.

(2-1-10) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, the heated reinforcing cordmember is embedded in the tire frame.

By embedding the reinforcing cord member in the tire frame while heatingthe reinforcing cord member in the reinforcing cord winding step assuch, when the heated reinforcing cord member comes into contact withthe outer circumference of the tire frame, the contact part of is meltedor softened. Therefore, it becomes easy to embed the reinforcing cordmember in the outer circumference of the tire frame.

(2-1-11) The manufacturing method of the tire may be configured so that,in the cord member winding step, the part of the outer circumference ofthe tire frame for embedding the reinforcing cord member is heated.

By heating the part of the outer circumference of the tire frame inwhich the reinforcing cord member is embedded as such, the heated partof the tire frame is melted or softened. Therefore, it becomes easy toembed the reinforcing cord member.

(2-1-12) The manufacturing method of the tire may be configured so that,in the cord member winding step, the reinforcing cord member is wound ina spiral shape in the circumferential direction of the outercircumference of the tire frame while pressing the reinforcing cordmember against the outer circumference of the tire frame.

When the reinforcing cord member is wound in the spiral shape whilepressing the reinforcing cord member against the outer circumference ofthe tire frame as such, the depth of embedding the reinforcing cordmember in the outer circumference of the tire frame may be adjusted.

(2-1-13) According to the manufacturing method, it may be configured sothat, in the cord member winding step, after winding the reinforcingcord member around the tire frame, the melted or softened part of theouter circumference of the tire frame is cooled.

By forcibly cooling the melted or softened part of the outercircumference of the tire frame after embedding the reinforcing cordmember as such, the melted or softened part of the outer circumferenceof the tire frame may be more quickly and rapidly cooled and solidifiedthan natural cooling. By cooling the outer circumference of the tiremore quickly than natural cooling, deformation of the outercircumference of the tire frame may be suppressed, and movement of thereinforcing cord member may be suppressed.

The tire of the second aspect of the invention may be configured asfollows as described in Embodiment 2-2.

(2-2-1) The tire of the second aspect of the invention may be configuredso that the manufacturing method further includes: a rougheningtreatment step of performing the roughening treatment on the outercircumferential surface of the tire frame by allowing a particle-shapedblasting abrasive to collide with the outer circumferential surface ofthe tire frame; and a superposing step of superposing atire-constituting rubber member on the outer circumferential surfacewhich has been subjected to the roughening treatment, via a bondingagent.

When the roughening treatment step is provided as such, theparticle-shaped blasting abrasive collides with the outercircumferential surface of the circular tire frame formed by using thethermoplastic resin material including a polyamide-based thermoplasticelastomer and another elastomer, and thus minute roughened unevenness isformed on the outer circumferential surface. The treatment of formingminute roughened unevenness by allowing the particle-shaped blastingabrasive to collide with the outer circumferential surface of the tireframe is referred to as the roughening treatment. Thereafter, thetire-constituting rubber member is superposed on the outercircumferential surface which has been subjected to the rougheningtreatment, via the bonding agent. Here, when the tire frame and thetire-constituting rubber member are integrated into each other, sincethe outer circumferential surface of the tire frame has been subjectedto the roughening treatment, bonding properties (adhesiveness) areenhanced due to the anchor effect. In addition, since the resin materialthat forms the tire frame is ploughed due to collision of the blastingabrasive, wettability of the outer circumferential surface is enhanced.Accordingly, the outer circumferential surface of the tire frame is heldin a state of being uniformly coated with the bonding agent, and thusthe bonding strength between the tire frame and the tire-constitutingrubber member may be ensured.

(2-2-2) In the tire of the second aspect of the invention, at least apart of the outer circumferential surface of the tire frame may be anuneven portion, and the uneven portion may be subjected to theroughening treatment in the roughening treatment step.

Even if at least a part of the outer circumferential surface of the tireframe is the uneven portion as such, by allowing abrasion material tocollide with the uneven portion, the area around a recess (walls at therecess, the bottom of the recess) is subjected to the rougheningtreatment, and thus the bonding strength between the tire frame and thetire-constituting rubber member may be ensured.

(2-2-3) The tire of the second aspect of the invention may be configuredsuch that the outer circumference of the tire frame is configured tohave a reinforcing layer that constitutes the uneven portion at theouter circumferential surface, and the reinforcing layer may beconfigured such that a coated cord member formed by coating thereinforcing cord with a resin material of the same kind as or differentfrom the resin material for forming the tire frame is wound in thecircumferential direction of the tire frame.

By configuring the outer circumference of the tire frame to have thereinforcing layer formed by winding the coated cord member in thecircumferential direction of the tire frame as such, the rigidity of thetire frame in the circumferential direction may be enhanced.

(2-2-4) In the tire of the second aspect of the invention, athermoplastic resin material may be used as the resin material forforming the coated cord member.

By using a thermoplastic material having thermoplasticity as the resinmaterial that is a component of the coated cord member as such, comparedto a case of using a thermosetting material as the resin material, thetire is easily manufactured and is easily recycled.

(2-2-5) The tire of the second aspect of the invention may be configuredso that, in the roughening treatment step, an area wider than the areafor superposing the tire-constituting rubber member is subjected to theroughening treatment.

When the area wider than the area for superposing the tire-constitutingrubber member is subjected to the roughening treatment in the rougheningtreatment step, the bonding strength between the tire frame and thetire-constituting rubber member may be reliably ensured.

(2-2-6) The tire of the second aspect of the invention may be configuredso that, in the roughening treatment step, the outer circumferentialsurface is subjected to the roughening treatment to have an arithmeticmean roughness Ra of 0.05 mm or greater.

When the outer circumferential surface of the tire frame is subjected tothe roughening treatment to have an arithmetic mean roughness Ra of 0.05mm or greater in the roughening treatment step as such, in a case wherethe tire-constituting rubber member, for example, in an unvulcanized orsemi-vulcanized state is superposed on the outer circumferential surfacewhich has been subjected to the roughening treatment, via the bondingagent, and is vulcanized, rubber of the tire-constituting rubber membermay be caused to flow to the bottom of the roughened uneven portionformed by the roughening treatment. When the rubber of thetire-constituting rubber member flows to the bottom of the rougheneduneven portion, a sufficient anchor effect is exhibited between theouter circumferential surface and the tire-constituting rubber member,and the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

(2-2-7) In the tire of the second aspect of the invention, a rubber inthe unvulcanized or semi-vulcanized state may be used as thetire-constituting rubber member.

In the case where the rubber in the unvulcanized or semi-vulcanizedstate is used as the tire-constituting rubber member as such, the rubberflows to the roughened uneven portion formed on the outercircumferential surface of the tire frame by the roughening treatmentwhen the tire-constituting rubber member is vulcanized. In addition,when vulcanization is completed, the anchor effect is exhibited by the(vulcanized) rubber that has flowed to the roughened uneven portion, andthus the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

“Vulcanized” is referred to as a state in which the degree ofvulcanization has reached the degree needed for a final product, and the“semi-vulcanized state” is referred to as a state in which the degree ofvulcanization is a higher than that of the unvulcanized state but hasnot reached the degree needed for a final product.

(2-2-8) The tire of the second aspect of the invention may be configuredto include: a circular tire frame that is formed using a thermoplasticresin material including a polyamide-based thermoplastic elastomer andanother elastomer, and has the outer circumferential surface which hasbeen subjected to the roughening treatment by allowing a particle-shapedblasting abrasive to collide with the outer circumferential surface; anda tire-constituting rubber member superposed on the outercircumferential surface that has been subjected to the rougheningtreatment, via a bonding agent.

When the circular tire frame which has been subjected to the rougheningtreatment is used as such, the bonding strength between the tire frameand the tire-constituting rubber member may be enhanced by the anchoreffect. In addition, since the outer circumferential surface has beensubjected to the roughening treatment, excellent wettability of thebonding agent is provided. Accordingly, the bonding agent is held in thestate of being uniformly applied onto the outer circumferential surfaceof the tire frame, the bonding strength between the tire frame and thetire-constituting rubber member is ensured, and thus peeling between thetire frame and the tire-constituting rubber member may be suppressed.

The tire of the third aspect of the invention may be configured asfollows as described in Embodiment 3-1.

(3-1-1) The tire of the third aspect of the invention may be configuredso that at least a part of the reinforcing cord member is embedded inthe outer circumference of the tire frame formed of a thermoplasticresin material in the third aspect of the invention in thecross-sectional view along the axial direction of the tire frame.

When a part of the reinforcing cord member is embedded in the outercircumference of the tire frame as such, a phenomenon in which airremains in the area around the cord during winding of the reinforcingcord member (incorporation of air) may further be suppressed. Whenincorporation of air into the area around the reinforcing cord member issuppressed, movement of the reinforcing cord member due to, a forceapplied during running is suppressed. Accordingly, for example, in thecase where a tire-constituting member is provided on the outercircumference of the tire frame to cover the entire reinforcing cordmember, since the movement of the reinforcing cord member is suppressed,an occurrence of peeling and the like between the members (including thetire frame) is suppressed, and durability is enhanced.

(3-1-2) The tire of the third aspect of the invention may be providedwith a tread formed of a material having higher wear resistance than thethermoplastic resin material on the outer side in the radial directionof the reinforcing cord layer.

By having a configuration in which the tread that comes into contactwith the road surface of the material having higher wear resistance thanthe thermoplastic resin material as such, the wear resistance of thetire may further be enhanced.

(3-1-3) In the tire of the third aspect of the invention, ⅕ or more ofthe diameter of the reinforcing cord member may be embedded in the outercircumference of the tire frame along the circumferential direction inthe cross-sectional view along the axial direction of the tire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord membermay be effectively suppressed, and thus movement of the reinforcing cordmember due to, for example, a force applied during running may furtherbe suppressed.

(3-1-4) The tire of the third aspect of the invention may be configuredso that the tire frame includes, on the inner side in the radialdirection, a bead portion that comes into contact with a bead seat and arim flange of a rim, and an annular bead core made of a metal materialis embedded in the bead portion.

By providing the bead portion which is a part for fitting onto the rimin the tire frame, and moreover, by embedding the annular bead core madeof the metal material in the bead portion as such, the tire frame (thatis, tire) may be firmly held on the rim, similarly to conventionalpneumatic tires made of rubber.

(3-1-5) The tire of the third aspect of the invention may be providedwith a sealing portion made of a material having higher sealingproperties (adhesion to the rim) than the thermoplastic resin material,in a part where the bead portion comes into contact with the rim.

By providing the sealing portion made of the material having highersealing properties than the thermoplastic resin material in the partwhere the tire frame and the rim come into contact with each other assuch, adhesion between the tire (the tire frame) and the rim may beenhanced. Accordingly, compared to a case where only the rim and thethermoplastic resin material are used, leakage of air in the tire mayfurther be suppressed. In addition, by providing the sealing portion,fittability onto the rim of the tire may be enhanced.

(3-1-6) The manufacturing method of the tire of the third aspect of theinvention may include: a tire frame piece forming step of forming a tireframe piece for constituting a part of the circular tire frame using thethermoplastic resin material including at least a polyamide-basedthermoplastic elastomer, and an acid-modified elastomer obtained byacid-modifying a thermoplastic elastomer other than the polyamide-basedthermoplastic elastomer, or a mixture of a thermoplastic elastomer otherthan the polyamide-based thermoplastic elastomer and an acid-modifiedelastomer obtained by acid-modifying the elastomer other than thepolyamide-based thermoplastic elastomer; a tire frame piece bonding stepof forming a tire frame by fusing two or more tire frame pieces, whichmake a pair, by applying heat to the bonding surfaces of the tire framepieces; and a reinforcing cord member winding step of winding areinforcing cord member around the outer circumference of the tire framein the circumferential direction to form a reinforcing cord layer.

(3-1-7) The manufacturing method of the tire may be configured so that,in the tire frame piece bonding step, the bonding surface of the tireframe piece is heated to a temperature equal to or higher than themelting point of the thermoplastic resin material that forms the tireframe piece.

When the bonding surface of the divided body is heated to thetemperature equal to or higher than the melting point of thethermoplastic resin material that forms the tire frame piece as such,fusing between the tire frame pieces may be sufficiently performed.Therefore, productivity of the tire may be enhanced while enhancingdurability of the tire.

(3-1-8) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, the reinforcing cord memberis wound around the outer circumference of the tire frame in a mannersuch that at least a part of the reinforcing cord member is embeddedwhile melting or softening the outer circumference of the tire frameformed in the tire frame piece bonding step.

By winding the reinforcing cord member around the outer circumference ofthe tire frame in a manner such that at least a part of the reinforcingcord member is embedded while melting and softening the outercircumference of the tire frame as such, the at least a part of thereinforcing cord member which is embedded and the melted or softenedthermoplastic resin material may be welded. Accordingly, incorporationof air between the outer circumference of the tire frame and thereinforcing cord member in the cross-sectional view along the axialdirection of the tire frame may further be suppressed. In addition, whenthe part in which the reinforcing cord member is embedded is cooled andsolidified, the fixed condition of the reinforcing cord member embeddedin the tire frame is enhanced.

(3-1-9) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, ⅕ or more of the diameterof the reinforcing cord may be embedded in the outer circumference ofthe tire frame in the cross-sectional view along the axial direction ofthe tire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord duringmanufacturing may be effectively suppressed, and moreover, the embeddedreinforcing cord member may become less likely to be caused to come outof the tire frame.

(3-1-10) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, the heated reinforcing cordmember is embedded in the tire frame.

By embedding the reinforcing cord member in the tire frame while heatingin the reinforcing cord member in the reinforcing cord winding step assuch, when the heated reinforcing cord member that comes into contactwith the outer circumference of the tire frame, the contact part ismelted or softened. Therefore, it becomes easy to embed the reinforcingcord member in the outer circumference of the tire frame.

(3-1-11) The manufacturing method of the tire may be configured so that,in the cord member winding step, the part of the outer circumference ofthe tire frame for embedding the reinforcing cord member is heated.

By heating the part of the outer circumference of the tire frame forembedding the reinforcing cord member as such, the heated part of thetire frame is melted or softened.

Therefore, it becomes easy to embed the reinforcing cord member.

(3-1-12) The manufacturing method of the tire may be configured so that,in the cord member winding step, the reinforcing cord member is wound ina spiral shape in the circumferential direction of the outercircumference of the tire frame while pressing the reinforcing cordmember against the outer circumference of the tire frame.

When the reinforcing cord member is wound in the spiral shape whilepressing the reinforcing cord member against the outer circumference ofthe tire frame as such, the depth of embedding the reinforcing cordmember in the outer circumference of the tire frame may be adjusted.

(3-1-13) According to the manufacturing method, it may be configuredsuch that, in the cord member winding step, after winding thereinforcing cord member around the tire frame, the melted or softenedpart of the outer circumference of the tire frame is cooled.

By forcibly cooling the melted or softened part of the outercircumference of the tire frame after embedding the reinforcing cordmember as such, the melted or softened part of the outer circumferenceof the tire frame may be more quickly and rapidly cooled and solidifiedthan natural cooling. By cooling the outer circumference of the tiremore quickly than natural cooling, deformation of the outercircumference of the tire frame may be suppressed, and movement of thereinforcing cord member may be suppressed.

The tire of the third aspect of the invention may be configured asfollows as described in Embodiment 3-2.

(3-2-1) The tire of the third aspect of the invention may be configuredso that the manufacturing method further includes: a rougheningtreatment step of performing the roughening treatment on the outercircumferential surface of the tire frame by allowing a particle-shapedblasting abrasive to collide with the outer circumferential surface ofthe tire frame; and a superposing step of superposing atire-constituting rubber member on the outer circumferential surfacewhich has been subjected to the roughening treatment, via a bondingagent.

When the roughening treatment step is provided as such, theparticle-shaped blasting abrasive collides with the outercircumferential surface of the circular tire frame formed by using thethermoplastic resin material, and thus minute roughened unevenness isformed on the outer circumferential surface. The treatment of formingminute roughened unevenness by allowing the blasting abrasive to collidewith the outer circumferential surface of the tire frame is referred toas the roughening treatment. Thereafter, the tire-constituting rubbermember is superposed on the outer circumferential surface which has beensubjected to the roughening treatment, via the bonding agent. Here, whenthe tire frame and the tire-constituting rubber member are integratedinto each other, since the outer circumferential surface of the tireframe has been subjected to the roughening treatment, bonding properties(adhesiveness) are enhanced due to the anchor effect. In addition, sincethe resin material that forms the tire frame is ploughed due tocollision of the blasting abrasive, wettability of the outercircumferential surface is enhanced. Accordingly, the outercircumferential surface of the tire frame is held in a state of beinguniformly coated with the bonding agent, and thus the bonding strengthbetween the tire frame and the tire-constituting rubber member may beensured.

(3-2-2) In the tire of the third aspect of the invention, at least apart of the outer circumferential surface of the tire frame may be anuneven portion, and the uneven portion may be subjected to theroughening treatment in the roughening treatment step.

Even if at least a part of the outer circumferential surface of the tireframe is the uneven portion as such, by allowing the blasting abrasiveto collide with the uneven portion, the area around a recess (walls atthe recess, the bottom of the recess) is subjected to the rougheningtreatment, and thus the bonding strength between the tire frame and thetire-constituting rubber member may be ensured.

(3-2-3) The tire of the third aspect of the invention may be configuredsuch that the outer circumference of the tire frame is configured tohave a reinforcing layer that constitutes the uneven portion at theouter circumferential surface, and the reinforcing layer may beconfigured such that a coated cord member formed by coating areinforcing cord with a resin material of the same kind as or differentfrom the resin material that forms the tire frame is wound in thecircumferential direction of the tire frame.

By configuring the outer circumference of the tire frame to have thereinforcing layer formed by winding the coated cord member in thecircumferential direction of the tire frame as such, the rigidity of thetire frame in the circumferential direction may be enhanced.

(3-2-4) In the tire of the third aspect of the invention, athermoplastic resin material may be used as the resin material that is acomponent of the coated cord member.

By using the thermoplastic material having thermoplasticity as the resinmaterial that is a component of the coated cord member as such, comparedto a case of using a thermosetting material as the resin material, thetire is easily manufactured and is easily recycled.

(3-2-5) The tire of the third aspect of the invention may be configuredso that, in the roughening treatment step, an area wider than the areafor superposing the tire-constituting rubber member is subjected to theroughening treatment.

When the area wider than the area for superposing the tire-constitutingrubber member is subjected to the roughening treatment in the rougheningtreatment step, the bonding strength between the tire frame and thetire-constituting rubber member may be reliably ensured.

(3-2-6) The tire of the third aspect of the invention may be configuredso that, in the roughening treatment step, the outer circumferentialsurface is subjected to the roughening treatment to have an arithmeticmean roughness Ra of 0.05 mm or greater.

When the outer circumferential surface of the tire frame is subjected tothe roughening treatment to have an arithmetic mean roughness Ra of 0.05mm or greater in the roughening treatment step as such, in a case wherethe tire-constituting rubber member, for example, in an unvulcanized orsemi-vulcanized state is superposed on the outer circumferential surfacewhich has been subjected to the roughening treatment, via the bondingagent, and then is vulcanized, rubber of the tire-constituting rubbermember may be caused to flow to the bottom of the roughened unevenportion formed by the roughening treatment. When the rubber of thetire-constituting rubber member flows to the bottom of the rougheneduneven portion, a sufficient anchor effect is exhibited between theouter circumferential surface and the tire-constituting rubber member,and the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

(3-2-7) In the tire of the third aspect of the invention, a rubber inthe unvulcanized or semi-vulcanized state may be used as thetire-constituting rubber member.

In the case where the rubber in the unvulcanized or semi-vulcanizedstate is used as the tire-constituting rubber member as such, the rubberflows to the roughened uneven portion formed on the outercircumferential surface of the tire frame by the roughening treatmentwhen the tire-constituting rubber member is vulcanized. In addition,when vulcanization is completed, the anchor effect is exhibited by the(vulcanized) rubber that has flowed to the roughened uneven portion, andthus the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

“Vulcanized” is referred to as a state in which the degree ofvulcanization has reached the degree needed for a final product, and the“semi-vulcanized state” is referred to as a state in which the degree ofvulcanization is higher than the unvulcanized state but has not reachedthe degree needed for a final product.

(3-2-9) The tire of the third aspect of the invention may be configuredto include: a circular tire frame that is formed using a thermoplasticresin material in the third aspect of the invention and has the outercircumferential surface which has been subjected to the rougheningtreatment by allowing a particle-shaped blasting abrasive to collidewith the outer circumferential surface; and a tire-constituting rubbermember superposed on the outer circumferential surface which has beensubjected to the roughening treatment, via the bonding agent.

When the circular tire frame which has been subjected to the rougheningtreatment is used as such, the bonding strength between the tire frameand the tire-constituting rubber member may be enhanced by the anchoreffect. In addition, since the outer circumferential surface has beensubjected to the roughening treatment, excellent wettability of thebonding agent is provided. Accordingly, the bonding agent is held in thestate of being uniformly applied onto the outer circumferential surfaceof the tire frame, the bonding strength between the tire frame and thetire-constituting rubber member is ensured, and thus peeling between thetire frame and the tire-constituting rubber member may be suppressed.

The tire of the fourth aspect of the invention may be configured asfollows as described in Embodiment 4-1.

(4-1-1) The tire of the fourth aspect of the invention may be configuredso that at least a part of the reinforcing cord member is embedded inthe outer circumference of the tire frame formed of the thermoplasticresin material in the cross-sectional view along the axial direction ofthe tire frame.

When a part of the reinforcing cord member is embedded in the outercircumference of the tire frame as such, a phenomenon in which airremains in the area around the cord during winding of the reinforcingcord member (incorporation of air) may further be suppressed. Whenincorporation of air into the area around the reinforcing cord member issuppressed, movement of the reinforcing cord member due to, for example,a force applied during running is suppressed. Accordingly, for example,in the case where the tire-constituting member is provided in the outercircumference of the tire frame to cover the entire reinforcing cordmember, since the movement of the reinforcing cord member is suppressed,an occurrence of peeling and the like between the members (including thetire frame) is suppressed, and durability is enhanced.

(4-1-2) The tire of the fourth aspect of the invention may be providedwith a tread formed of a material having higher wear resistance than thethermoplastic resin material on the outer side in the radial directionof the reinforcing cord layer.

By having configuration in which the tread that comes into contact withthe road surface is formed of the material having higher wear resistancethan the thermoplastic resin material as such, the wear resistance ofthe tire may further be enhanced.

(4-1-3) In the tire of the fourth aspect of the invention, ⅕ or more ofthe diameter of the reinforcing cord member may be embedded in the outercircumference of the tire frame along the circumferential direction inthe cross-sectional view along the axial direction of the tire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord membermay be effectively suppressed, and thus movement of the reinforcing cordmember due to, for example, a force applied during running may furtherbe suppressed.

(4-1-4) The tire of the fourth aspect of the invention may be configuredso that the tire frame includes, on the inner side in the radialdirection, a bead portion that comes into contact with a bead seat and arim flange of a rim, and a annular bead core made of the metal materialis embedded in the bead portion.

By providing the bead portion which is a part for fitting onto the rimin the tire frame, and moreover, by embedding the annular bead core madeof a metal material in the bead portion as such, the tire frame (thatis, tire) may be firmly held on the rim, similarly to conventionalpneumatic tires made of rubber.

(4-1-5) The tire of the fourth aspect of the invention may be providedwith a sealing portion made of a material having higher sealingproperties (adhesion to the rim) than the thermoplastic resin material,in a part where the bead portion comes into contact with the rim.

By providing the sealing portion made of the material having highersealing properties than the thermoplastic resin material in the partwhere the tire frame and the rim come into contact with each other assuch, adhesion between the tire (the tire frame) and the rim may beenhanced. Accordingly, compared to a case where only the rim and thethermoplastic resin material are used, leakage of air in the tire mayfurther be suppressed. In addition, by providing the sealing portion,fittability onto the rim of the tire may be enhanced.

(4-1-6) The tire of the fourth aspect of the invention may bemanufactured according to the manufacturing method that includes: a tireframe piece forming step of forming a tire frame piece for constitutinga part of the circular tire frame using at least the thermoplastic resinmaterial; a tire frame piece bonding step of forming a tire frame byfusing two or more tire frame pieces, which form a pair, by applyingheat to the bonding surfaces of the tire frame pieces; and a reinforcingcord member winding step of winding a reinforcing cord member around theouter circumference of the tire frame in the circumferential directionto form a reinforcing cord layer.

(4-1-7) The manufacturing method may be configured so that, in the tireframe piece bonding step, the bonding surface of the tire frame piece isheated to a temperature equal to or higher than the melting point (forexample, the melting point +10° C. to +150° C.) of the thermoplasticresin material that forms the tire frame piece.

When the bonding surface of the divided body is heated to a temperatureequal to or higher than the melting point of the thermoplastic resinmaterial that forms the tire frame piece as such, fusing between thetire frame pieces may be sufficiently performed. Therefore, productivityof the tire may be enhanced while enhancing durability of the tire.

(4-1-8) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, the reinforcing cord memberis wound around the outer circumference of the tire frame in a mannersuch that at least a part of the reinforcing cord member is embeddedwhile melting or softening the outer circumference of the tire frameformed in the tire frame piece bonding step.

By winding the reinforcing cord member around the outer circumference ofthe tire frame in a manner such that at least a part of the reinforcingcord member is embedded while melting and softening the outercircumference of the tire frame as such, the at least a part of thereinforcing cord member which is embedded and the melted or softenedthermoplastic resin material may be welded. Accordingly, incorporationof air between the outer circumference of the tire frame and thereinforcing cord member in the cross-sectional view along the axialdirection of the tire frame may further be suppressed. In addition, whenthe part in which the reinforcing cord member is embedded is cooled andsolidified, the fixed condition of the reinforcing cord member embeddedin the tire frame is enhanced.

(4-1-9) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, ⅕ or more of the diameterof the reinforcing cord may be embedded in the outer circumference ofthe tire frame in the cross-sectional view along the axial direction ofthe tire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord duringmanufacturing may be effectively suppressed, and moreover, the embeddedreinforcing cord member may become less likely to be caused to come outof the tire frame.

(4-1-10) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, the heated reinforcing cordmember is embedded in the tire frame.

By embedding the reinforcing cord member in the tire frame while heatingthe reinforcing cord member in the reinforcing cord winding step assuch, when the heated reinforcing cord member comes into contact withthe outer circumference of the tire frame, the contact part is melted orsoftened. Therefore, it becomes easy to embed the reinforcing cordmember in the outer circumference of the tire frame.

(4-1-11) The manufacturing method of the tire may be configured so that,in the cord member winding step, the part of the outer circumference ofthe tire frame for embedding the reinforcing cord member is heated.

By heating the part of the outer circumference of the tire frame forembedding the reinforcing cord member as such, the heated part of thetire frame is melted or softened. Therefore, it becomes easy to embedthe reinforcing cord member.

(4-1-12) The manufacturing method of the tire may be configured so that,in the cord member winding step, the reinforcing cord member is wound ina spiral shape in the circumferential direction of the outercircumference of the tire frame while pressing the reinforcing cordmember against the outer circumference of the tire frame.

When the reinforcing cord member is wound in the spiral shape whilepressing the reinforcing cord member against the outer circumference ofthe tire frame as such, the width of embedding the reinforcing cordmember in the outer circumference of the tire frame may be adjusted.

(4-1-13) According to the manufacturing method, it may be configured sothat, in the cord member winding step, after winding the reinforcingcord member around the tire frame, the melted or softened part of theouter circumference of the tire frame is cooled.

By forcibly cooling the melted or softened part of the outercircumference of the tire frame after embedding the reinforcing cordmember as such, the melted or softened part of the outer circumferenceof the tire frame may be more quickly and rapidly cooled and solidifiedthan natural cooling. By cooling the outer circumference of the tiremore quickly than natural cooling, deformation of the outercircumference of the tire frame may be suppressed, and movement of thereinforcing cord member may be suppressed.

The tire of the fourth aspect of the invention may be configured asfollows as described in Embodiment 4-2.

(4-2-1) The tire of the fourth aspect of the invention may be configuredso that the manufacturing method further includes: a rougheningtreatment step of performing the roughening treatment on the outercircumferential surface of the tire frame by allowing a particle-shapedblasting abrasive to collide with the outer circumferential surface ofthe tire frame; and a superposing step of superposing atire-constituting rubber member on the outer circumferential surfacewhich has been subjected to the roughening treatment, via a bondingagent.

When the roughening treatment step is provided as such, theparticle-shaped blasint abrasive collides with the outer circumferentialsurface of the circular tire frame formed using the thermoplastic resinmaterial, and thus minute roughened unevenness is formed on the outercircumferential surface. The treatment of forming minute roughenedunevenness by allowing the blasting abrasive to collide with the outercircumferential surface of the tire frame is referred to as theroughening treatment. Thereafter, the tire-constituting rubber member issuperposed on the outer circumferential surface which has been subjectedto the roughening treatment, via the bonding agent. Here, when the tireframe and the tire-constituting rubber member are integrated into eachother, since the outer circumferential surface of the tire frame hasbeen subjected to the roughening treatment, bonding properties(adhesiveness) are enhanced due to the anchor effect. In addition, sincethe thermoplastic resin material that forms the tire frame is plougheddue to collision of the blasting abrasive, wettability of the outercircumferential surface is enhanced. Accordingly, the outercircumferential surface of the tire frame is held in a state of beinguniformly coated with the bonding agent, and thus the bonding strengthbetween the tire frame and the tire-constituting rubber member may beensured.

(4-2-2) In the tire of the fourth aspect of the invention, at least apart of the outer circumferential surface of the tire frame may be anuneven portion, and the uneven portion may be subjected to theroughening treatment in the roughening treatment step.

Even if at least a part of the outer circumferential surface of the tireframe is the uneven portion as such, by allowing the blasting abrasiveto collide with the uneven portion, the area around a recess (walls atthe recess, the bottom of the recess) is subjected to the rougheningtreatment, and thus the bonding strength between the tire frame and thetire-constituting rubber member may be ensured.

(4-2-3) In the tire of the fourth aspect of the invention, the outercircumference of the tire frame is configured to have a reinforcinglayer that constitutes the uneven portion at the outer circumferentialsurface, and the reinforcing layer may be configured so that a coatedcord member formed by coating the reinforcing cord with a resin materialof the same kind as or different from the resin material that forms thetire frame is wound in the circumferential direction of the tire frame.

By configuring the outer circumference of the tire frame to have thereinforcing layer formed by winding the coated cord member in thecircumferential direction of the tire frame as such, the rigidity of thetire frame in the circumferential direction may be enhanced.

(4-2-4) In the tire of the fourth aspect of the invention, athermoplastic resin material may be used as the resin material that is acomponent of the coated cord member.

By using the thermoplastic material having thermoplasticity as the resinmaterial that is a component of the coated cord member as such, comparedto a case of using a thermosetting material as the resin material, thetire is easily manufactured and is easily recycled.

(4-2-5) The tire of the fourth aspect of the invention may be configuredso that, in the roughening treatment step, an area wider than the areafor superposing the tire-constituting rubber member is subjected to theroughening treatment.

When the area wider than the area for superposing the tire-constitutingrubber member is subjected to the roughening treatment in the rougheningtreatment step, the bonding strength between the tire frame and thetire-constituting rubber member may be reliably ensured.

(4-2-6) The tire of the fourth aspect of the invention may be configuredso that, in the roughening treatment step, the outer circumferentialsurface is subjected to the roughening treatment to have an arithmeticmean roughness Ra of 0.05 mm or greater.

When the outer circumferential surface of the tire frame is subjected tothe roughening treatment to have an arithmetic mean roughness Ra of 0.05mm or greater in the roughening treatment step as such, in a case wherethe tire-constituting rubber member, for example, in an unvulcanized orsemi-vulcanized state is superposed on the outer circumferential surfacewhich has been subjected to the roughening treatment, via the bondingagent, and is vulcanized, rubber of the tire-constituting rubber membermay be caused to flow to the bottom of the roughened uneven portionformed by the roughening treatment. When the rubber of thetire-constituting rubber member flows to the bottom of the rougheneduneven portion, a sufficient anchor effect is exhibited between theouter circumferential surface and the tire-constituting rubber member,and the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

(4-2-7) In the tire of the fourth aspect of the invention, a rubber inthe unvulcanized or semi-vulcanized state may be used as thetire-constituting rubber member.

In the case where the rubber in the unvulcanized or semi-vulcanizedstate is used as the tire-constituting rubber member as such, the rubberflows to the roughened uneven portion formed on the outercircumferential surface of the tire frame by the roughening treatmentwhen the tire-constituting rubber member is vulcanized. In addition,when vulcanization is completed, the anchor effect is exhibited by the(vulcanized) rubber that has flowed to the roughened uneven portion, andthus the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

“Vulcanized” is referred to as a state in which the degree ofvulcanization reaches the degree needed for a final product, and the“semi-vulcanized state” is referred to as a state in which thevulcanization degree is higher than the degree of the unvulcanized statebut has not reached the degree needed for a final product.

(4-2-8) The tire of the fourth aspect of the invention may be configuredto include: a circular tire frame that is formed using a resin materialand has the outer circumferential surface which has been subjected tothe roughening treatment by allowing a particle-shaped blasting abrasiveto collide with on the outer circumferential surface; and atire-constituting rubber member superposed on the outer circumferentialsurface which has been subjected to the roughening treatment, via thebonding agent.

When the circular tire frame which has been subjected to the rougheningtreatment is used as such, the bonding strength between the tire frameand the tire-constituting rubber member may be enhanced by the anchoreffect. In addition, since the outer circumferential surface has beensubjected to the roughening treatment, excellent wettability of thebonding agent is provided. Accordingly, the bonding agent is held in thestate of being uniformly applied onto the outer circumferential surfaceof the tire frame, the bonding strength between the tire frame and thetire-constituting rubber member is ensured, and thus peeling between thetire frame and the tire-constituting rubber member may be suppressed.

While the specific modes of the fourth aspect of the invention aredescribed using Embodiment 4-1 and Embodiment 4-2, the fourth aspect ofthe invention is not limited to the above-described modes.

The tire of the fifth aspect of the invention may be configured asfollows as described in Embodiment 5-1.

(5-1-1) The tire of the fifth aspect of the invention may be configuredso that at least a part of the reinforcing cord member is embedded inthe outer circumference of the tire frame formed of the thermoplasticresin material in the cross-sectional view along the axial direction ofthe tire frame.

When a part of the reinforcing cord member is embedded in the outercircumference of the tire frame as such, a phenomenon in which airremains in the area around the cord during winding of the reinforcingcord member (incorporation of air) may further be suppressed. Whenincorporation of air into the area around the reinforcing cord member issuppressed, movement of the reinforcing cord member due to, for example,a force applied during running is suppressed. Accordingly, for example,in the case where the tire-constituting member is provided in the outercircumference of the tire frame to cover the entire reinforcing cordmember, since the movement of the reinforcing cord member is suppressed,an occurrence of peeling and the like between the members (including thetire frame) is suppressed, and durability is enhanced.

(5-1-2) The tire of the fifth aspect of the invention may be providedwith a tread formed of a material having higher wear resistance than thethermoplastic resin material on the outer side in the radial directionof the reinforcing cord layer.

By having a configuration in which the tread that comes into contactwith the road surface is formed of the material having higher wearresistance than the thermoplastic resin material as such, the wearresistance of the tire may further be enhanced.

(5-1-3) In the tire of the fifth aspect of the invention, ⅕ or more ofthe diameter of the reinforcing cord member may be embedded in the outercircumference of the tire frame along the circumferential direction inthe cross-sectional view along the axial direction of the tire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord membermay be effectively suppressed, and thus movement of the reinforcing cordmember due to, for example, a force applied during running may furtherbe suppressed.

(5-1-4) The tire of the fifth aspect of the invention may be configuredso that the tire frame includes, on the inner side in the radialdirection, a bead portion that comes into contact with a bead seat and arim flange of a rim, and a annular bead core made of a metal material isembedded in the bead portion.

By providing the bead portion which is a part for fitting onto the rimin the tire frame, and moreover, by embedding the annular bead core madeof a metal material in the bead portion as such, the tire frame (thatis, tire) may be firmly held on the rim, similarly to conventionalpneumatic tires made of rubber.

(5-1-5) The tire of the fifth aspect of the invention may be providedwith a sealing portion made of a material having higher sealingproperties (adhesion to the rim) than the thermoplastic resin material,in a part where the bead portion comes into contact with the rim.

By providing the sealing portion made of the material having highersealing properties than the thermoplastic resin material in the partwhere the tire frame and the rim come into contact with each other assuch, adhesion between the tire (the tire frame) and the rim may beenhanced. Accordingly, compared to a case where only the rim and thethermoplastic resin material are used, leakage of air in the tire mayfurther be suppressed. In addition, by providing the sealing portion,fittability onto the rim of the tire may be enhanced.

(5-1-6) The tire of the fifth aspect of the invention may bemanufactured according to a manufacturing method that includes: a tireframe piece forming step of forming a tire frame piece for constitutinga part of the circular tire frame using at least a thermoplastic resinmaterial; a tire frame piece bonding step of forming a tire frame byfusing two or more tire frame pieces, which make a pair, by applyingheat to the bonding surfaces of the tire frame pieces; and a reinforcingcord member winding step of winding a reinforcing cord member around theouter circumference of the tire frame in the circumferential directionto form a reinforcing cord layer.

(5-1-7) The manufacturing method may be configured so that, in the tireframe piece bonding step, the bonding surface of the tire frame piece isheated to a temperature equal to or higher than the melting point (forexample, the melting point +10° C. to +150° C.) of the thermoplasticresin material that forms the tire frame piece.

When the bonding surface of the divided body is heated to a temperatureequal to or higher than the melting point of the thermoplastic resinmaterial that forms the tire frame piece as such, fusing between thetire frame pieces may be sufficiently performed. Therefore, productivityof the tire may be enhanced while enhancing durability of the tire.

(5-1-8) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, the reinforcing cord memberis wound around the outer circumference of the tire frame in a mannersuch that at least a part of the reinforcing cord member is embeddedwhile melting or softening the outer circumference of the tire frameformed in the tire frame piece bonding step.

By winding the reinforcing cord member around the outer circumference ofthe tire frame in a manner such that at least a part of the reinforcingcord member is embedded while melting and softening the outercircumference of the tire frame as such, the at least a part of thereinforcing cord member which is embedded and the melted or softenedthermoplastic resin material may be welded. Accordingly, incorporationof air between the outer circumference of the tire frame and thereinforcing cord member in the cross-sectional view along the axialdirection of the tire frame may further be suppressed. In addition, whenthe part in which the reinforcing cord member is embedded is cooled andsolidified, the fixed condition of the reinforcing cord member embeddedin the tire frame is enhanced.

(5-1-9) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, ⅕ or more of the diameterof the reinforcing cord may be embedded in the outer circumference ofthe tire frame in the cross-sectional view along the axial direction ofthe tire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord duringmanufacturing may be effectively suppressed, and moreover, the embeddedreinforcing cord member may become less likely to be caused to come outof the tire frame.

(5-1-10) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, the heated reinforcing cordmember is embedded in the tire frame.

By embedding the reinforcing cord member in the tire frame while heatingthe reinforcing cord member in the reinforcing cord winding step assuch, when the heated reinforcing cord member comes into contact withthe outer circumference of the tire frame, the contact part is melted orsoftened. Therefore, it becomes easy to embed the reinforcing cordmember in the outer circumference of the tire frame.

(5-1-11) The manufacturing method of the tire may be configured so that,in the cord member winding step, the part of the outer circumference ofthe tire frame in which the reinforcing cord member is embedded isheated.

By heating the part of the outer circumference of the tire frame forembedding the reinforcing cord member as such, the heated part of thetire frame is melted or softened. Therefore, it becomes easy to embedthe reinforcing cord member.

(5-1-12) The manufacturing method of the tire may be configured so that,in the cord member winding step, the reinforcing cord member is wound ina spiral shape in the circumferential direction of the outercircumference of the tire frame while pressing the reinforcing cordmember against the outer circumference of the tire frame.

When the reinforcing cord member is wound in the spiral shape whilepressing the reinforcing cord member against the outer circumference ofthe tire frame as such, the depth of embedding the reinforcing cordmember in the outer circumference of the tire frame may be adjusted.

(5-1-13) According to the manufacturing method, it may be configured sothat, in the cord member winding step, after winding the reinforcingcord member around the tire frame, the melted or softened part of theouter circumference of the tire frame is cooled.

By forcibly cooling the melted or softened part of the outercircumference of the tire frame after embedding the reinforcing cordmember as such, the melted or softened part of the outer circumferenceof the tire frame may be more quickly and rapidly cooled and solidifiedthan natural cooling. By cooling the outer circumference of the tiremore quickly than natural cooling, deformation of the outercircumference of the tire frame may be suppressed, and movement of thereinforcing cord member may be suppressed.

The tire of the fifth aspect of the invention may be configured asfollows as described in Embodiment 5-2.

(5-2-1) The tire of the fifth aspect of the invention may be configuredsuch that the manufacturing method further includes: a rougheningtreatment step of performing the roughening treatment on the outercircumferential surface of the tire frame by allowing a particle-shapedblasting abrasive to collide with the outer circumferential surface ofthe tire frame; and a superposing step of superposing atire-constituting rubber member on the outer circumferential surfacewhich has been subjected to the roughening treatment, via a bondingagent.

When the roughening treatment step is provided as such, theparticle-shaped blasting abrasive collides with the outercircumferential surface of the circular tire frame formed using thethermoplastic resin material, and thus minute roughened unevenness isformed on the outer circumferential surface. The treatment of formingminute roughened unevenness by allowing the blasting abrasive to collidewith the outer circumferential surface of the tire frame is referred toas the roughening treatment. Thereafter, the tire-constituting rubbermember is superposed on the outer circumferential surface which has beensubjected to the roughening treatment, via the bonding agent. Here, whenthe tire frame and the tire-constituting rubber member are integratedinto each other, since the outer circumferential surface of the tireframe has been subjected to the roughening treatment, bonding properties(bonding properties) are enhanced due to the anchor effect. In addition,since the resin material that forms the tire frame is ploughed due tocollision of the blasting abrasive, wettability of the outercircumferential surface is enhanced. Accordingly, the outercircumferential surface of the tire frame is held in a state of beinguniformly coated with the bonding agent, and thus the bonding strengthbetween the tire frame and the tire-constituting rubber member may beensured.

(5-2-2) In the tire of the fifth aspect of the invention, at least apart of the outer circumferential surface of the tire frame may be anuneven portion, and the uneven portion may be subjected to theroughening treatment in the roughening treatment step.

Even if at least a part of the outer circumferential surface of the tireframe is the uneven portion as such, by allowing the blasting abrasiveto collide with the uneven portion, the area around a recess (walls atthe recess, the bottom of the recess) is subjected to the rougheningtreatment, and thus the bonding strength between the tire frame and thetire-constituting rubber member may be ensured.

(5-2-3) The fifth aspect of the invention may be configured such thatthe outer circumference of the tire frame is configured to have areinforcing layer that constitutes the uneven portion at the outercircumferential surface, and the reinforcing layer may be configuredsuch that a coated cord member formed by coating a reinforcing cord witha resin material of the same kind as or a different from the resinmaterial that forms the tire frame is wound in the circumferentialdirection of the tire frame.

By configuring the outer circumference of the tire frame to have thereinforcing layer formed by winding the coated cord member in thecircumferential direction of the tire frame as such, the rigidity of thetire frame in the circumferential direction may be enhanced.

(5-2-4) In the tire of the fifth aspect of the invention, athermoplastic resin material may be used as the resin material that is acomponent of the coated cord member.

By using the thermoplastic material having thermoplasticity as the resinmaterial that is a component of the coated cord member as such, comparedto a case of using a thermosetting material as the resin material, thetire is easily manufactured and is easily recycled.

(5-2-5) The tire of the fifth aspect of the invention may be configuredso that, in the roughening treatment step, an area wider than the areafor superposing the tire-constituting rubber member is subjected to theroughening treatment.

When the area wider than the area for superposing the tire-constitutingrubber member is subjected to the roughening treatment in the rougheningtreatment step, the bonding strength between the tire frame and thetire-constituting rubber member may be reliably ensured.

(5-2-6) The tire of the fifth aspect of the invention may be configuredso that, in the roughening treatment step, the outer circumferentialsurface is subjected to the roughening treatment to have an arithmeticmean roughness Ra of 0.05 mm or greater.

When the outer circumferential surface of the tire frame is subjected tothe roughening treatment to have an arithmetic mean roughness Ra of 0.05mm or greater in the roughening treatment step as such, in a case wherethe tire-constituting rubber member, for example, in an unvulcanized orsemi-vulcanized state is superposed on the outer circumferential surfacewhich has been subjected to the roughening treatment, via the bondingagent, and is vulcanized, rubber of the tire-constituting rubber membermay be caused to flow to the bottom of the roughened uneven portionformed by the roughening treatment. When the rubber of thetire-constituting rubber member flows to the bottom of the rougheneduneven portion, a sufficient anchor effect is exhibited between theouter circumferential surface and the tire-constituting rubber member,and the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

(5-2-7) In the tire of the fifth aspect of the invention, a rubber inthe unvulcanized or semi-vulcanized state may be used as thetire-constituting rubber member.

In the case where the rubber in the unvulcanized or semi-vulcanizedstate is used as the tire-constituting rubber member as such, the rubberflows to the roughened uneven portion formed on the outercircumferential surface of the tire frame by the roughening treatmentwhen the tire-constituting rubber member is vulcanized. In addition,when vulcanization is completed, the anchor effect is exhibited by the(vulcanized) rubber that has flowed to the roughened uneven portion, andthus the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

“Vulcanized” is referred to as a state in which the degree ofvulcanization reaches the degree needed for a final product, and the“semi-vulcanized state” is referred to as a state in which thevulcanization degree is higher than the unvulcanized state but has notreached the degree needed for a final product.

(5-2-8) The tire of the fifth aspect of the invention may be configuredto include: a circular tire frame that is formed using the resinmaterial and has the outer circumferential surface which has beensubjected to the roughening treatment by allowing a particle-shapedblasting abrasive to collide with the outer circumferential surface; anda tire-constituting rubber member superposed on the outercircumferential surface which has been subjected to the rougheningtreatment, via the bonding agent.

When the circular tire frame which has been subjected to the rougheningtreatment is used as such, the bonding strength between the tire frameand the tire-constituting rubber member may be enhanced by the anchoreffect. In addition, since the outer circumferential surface has beensubjected to the roughening treatment, excellent wettability of thebonding agent is provided. Accordingly, the bonding agent is held in thestate of being uniformly applied onto the outer circumferential surfaceof the tire frame, the bonding strength between the tire frame and thetire-constituting rubber member is ensured, and thus peeling between thetire frame and the tire-constituting rubber member may be suppressed.

While the specific modes of the fifth aspect of the invention have beendescribed using Embodiment 5-1 and Embodiment 5-2, the fifth aspect ofthe invention is not limited to the above-described modes.

The tire of the sixth aspect of the invention may be configured asfollows as described in Embodiment 6-1.

(6-1-1) The tire of the sixth aspect of the invention may be configuredso that at least a part of the reinforcing cord member is embedded inthe outer circumference of the tire frame formed of the thermoplasticresin material in the cross-sectional view along the axial direction ofthe tire frame.

When a part of the reinforcing cord member is embedded in the outercircumference of the tire frame as such, a phenomenon in which airremains in the area around the cord during winding of the reinforcingcord member (incorporation of air) may further be suppressed. Whenincorporation of air into the area around the reinforcing cord member issuppressed, movement of the reinforcing cord member due to, for example,a force applied during running is suppressed. Accordingly, for example,in the case where the tire-constituting member is provided on the outercircumference of the tire frame to cover the entire reinforcing cordmember, since the movement of the reinforcing cord member is suppressed,an occurrence of peeling and the like between the members (including thetire frame) is suppressed, and durability is enhanced.

(6-1-2) The tire of the sixth aspect of the invention may be providedwith a tread formed of a material having higher wear resistance than thethermoplastic resin material on the outer side in the radial directionof the reinforcing cord layer.

By having a configuration in which the tread that comes into contactwith the road surface is formed of a material having higher wearresistance than the thermoplastic resin material as such, the wearresistance of the tire may further be enhanced.

(6-1-3) In the tire of the sixth aspect of the invention, ⅕ or more ofthe diameter of the reinforcing cord member may be embedded in the outercircumference of the tire frame along the circumferential direction inthe cross-sectional view along the axial direction of the tire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord membermay be effectively suppressed, and thus movement of the reinforcing cordmember due to, for example, a force applied during running may furtherbe suppressed.

(6-1-4) The tire of the sixth aspect of the invention may be configuredso that the tire frame includes, on the inner side in the radialdirection, a bead portion that comes into contact with a bead seat and arim flange of a rim, and an annular bead core made of a metal materialis embedded in the bead portion.

By providing the bead portion which is a part for fitting onto the rimin the tire frame, and moreover, by embedding the annular bead core madeof the metal material in the bead portion as such, the tire frame (thatis, tire) may be firmly held on the rim, similarly to conventionalpneumatic tires made of rubber.

(6-1-5) The tire of the sixth aspect of the invention may be providedwith a sealing portion made of a material having higher sealingproperties (adhesion to the rim) than the thermoplastic resin material,in a part where the bead portion comes into contact with the rim.

By providing the sealing portion made of the material having highersealing properties than the thermoplastic resin material in the partwhere the tire frame and the rim come into contact with each other assuch, adhesion between the tire (the tire frame) and the rim may beenhanced. Accordingly, compared to a case where only the rim and thethermoplastic resin material are used, leakage of air in the tire mayfurther be suppressed. In addition, by providing the sealing portion,fittability onto the rim of the tire may be enhanced.

(6-1-6) The tire of the sixth aspect of the invention may bemanufactured according to a manufacturing method that includes: a tireframe piece forming step of forming a tire frame piece for constitutinga part of a circular tire frame using at least a thermoplastic resinmaterial; a tire frame piece bonding step of forming a tire frame byfusing two or more tire frame pieces, which make a pair, by applyingheat to the bonding surfaces of the tire frame pieces; and a reinforcingcord member winding step of winding a reinforcing cord member around theouter circumference of the tire frame in the circumferential directionto form a reinforcing cord layer.

(6-1-7) The manufacturing method may be configured so that, in the tireframe piece bonding step, the bonding surface of the tire frame piece isheated to a temperature equal to or higher than the melting point (forexample, the melting point +10° C. to +150° C.) of the thermoplasticresin material that forms the tire frame piece.

When the bonding surface of the divided body is heated to a temperatureequal to or higher than the melting point of the thermoplastic resinmaterial that forms the tire frame piece as such, fusing between thetire frame pieces may be sufficiently performed. Therefore, productivityof the tire may be enhanced while enhancing durability of the tire.

(6-1-8) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, the reinforcing cord memberis wound around the outer circumference of the tire frame in a mannersuch that at least a part of the reinforcing cord member is embeddedwhile melting or softening the outer circumference of the tire frameformed in the tire frame piece bonding step.

By winding the reinforcing cord member around the outer circumference ofthe tire frame in a manner such that at least a part of the reinforcingcord member is embedded while melting and softening the outercircumference of the tire frame as such, the at least a part of thereinforcing cord member which is embedded and the melted or softenedthermoplastic resin material may be welded. Accordingly, incorporationof air between the outer circumference of the tire frame and thereinforcing cord member in the cross-sectional view along the axialdirection of the tire frame may further be suppressed. In addition, whenthe part in which the reinforcing cord member is embedded is cooled andsolidified, the fixed condition of the reinforcing cord member embeddedin the tire frame is enhanced.

(6-1-9) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, ⅕ or more of the diameterof the reinforcing cord may be embedded in the outer circumference ofthe tire frame in the cross-sectional view along the axial direction ofthe tire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord duringmanufacturing may be effectively suppressed, and moreover, the embeddedreinforcing cord member may become less likely to be caused to come outof the tire frame.

(6-1-10) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, the heated reinforcing cordmember is embedded in the tire frame.

By embedding the reinforcing cord member in the tire frame while heatingthe reinforcing cord member in the reinforcing cord winding step assuch, when the heated reinforcing cord member comes into contact withthe outer circumference of the tire frame, the contact part is melted orsoftened. Therefore, it becomes easy to embed the reinforcing cordmember in the outer circumference of the tire frame.

(6-1-11) The manufacturing method of the tire may be configured so that,in the cord member winding step, the part of the outer circumference ofthe tire frame for embedding the reinforcing cord member is heated.

By heating the part of the outer circumference of the tire frame forembedding the reinforcing cord member as such, the heated part of thetire frame is melted or softened. Therefore, it becomes easy to embedthe reinforcing cord member.

(6-1-12) The manufacturing method of the tire may be configured so that,in the cord member winding step, the reinforcing cord member is wound ina spiral shape in the circumferential direction of the outercircumference of the tire frame while pressing the reinforcing cordmember against the outer circumference of the tire frame.

When the reinforcing cord member is wound in the spiral shape whilepressing the reinforcing cord member against the outer circumference ofthe tire frame as such, the depth of embedding the reinforcing cordmember in the outer circumference of the tire frame may be adjusted.

(6-1-13) According to the manufacturing method, it may be configured sothat, in the cord member winding step, after winding the reinforcingcord member around the tire frame, the melted or softened part of theouter circumference of the tire frame is cooled.

By forcibly cooling the melted or softened part of the outercircumference of the tire frame after embedding the reinforcing cordmember as such, the melted or softened part of the outer circumferenceof the tire frame may be more quickly and rapidly cooled and solidifiedthan natural cooling. By cooling the outer circumference of the tiremore quickly than natural cooling, deformation of the outercircumference of the tire frame may be suppressed, and movement of thereinforcing cord member may be suppressed.

The tire of the sixth aspect of the invention may be configured asfollows as described in Embodiment 6-2.

(6-2-1) The tire of the sixth aspect of the invention may be configuredso that the manufacturing method further includes: a rougheningtreatment step of performing the roughening treatment on the outercircumferential surface of the tire frame by allowing a particle-shapedblasting abrasive to collide with the outer circumferential surface ofthe tire frame; and a superposing step of superposing atire-constituting rubber member on the outer circumferential surfacewhich has been subjected to the roughening treatment, via a bondingagent.

When the roughening treatment step is provided as such, theparticle-shaped blastinb abrasive collides with the outercircumferential surface of the circular tire frame formed using thethermoplastic resin material, and thus minute roughened unevenness isformed on the outer circumferential surface. The treatment of formingminute roughened unevenness by allowing the blasting abrasive to collidewith the outer circumferential surface of the tire frame is referred toas the roughening treatment. Thereafter, the tire-constituting rubbermember is superposed on the outer circumferential surface subjected tothe roughening treatment, via the bonding agent. Here, when the tireframe and the tire-constituting rubber member are integrated into eachother, since the outer circumferential surface of the tire frame hasbeen subjected to the roughening treatment, bonding properties(adhesiveness) are enhanced due to the anchor effect. In addition, sincethe thermoplastic resin material that forms the tire frame is plougheddue to collision of the blasting abrasive, wettability of the outercircumferential surface is enhanced. Accordingly, the outercircumferential surface of the tire frame is held in a state of beinguniformly coated with the bonding agent, and thus the bonding strengthbetween the tire frame and the tire-constituting rubber member may beensured.

(6-2-2) In the tire of the sixth aspect of the invention, at least apart of the outer circumferential surface of the tire frame may be anuneven portion, and the uneven portion may be subjected to theroughening treatment in the roughening treatment step.

Even if at least a part of the outer circumferential surface of the tireframe is the uneven portion as such, by allowing the blasting abrasiveto collide with the uneven portion, the area around a recess (walls atthe recess, the bottom of the recess) is subjected to the rougheningtreatment, and thus the bonding strength between the tire frame and thetire-constituting rubber member may be ensured.

(6-2-3) In the tire of the sixth aspect of the invention, the outercircumference of the tire frame is configured to have a reinforcinglayer that constitutes the uneven portion at the outer circumferentialsurface, and the reinforcing layer may be configured so that a coatedcord member formed by coating a reinforcing cord with a resin materialof the same kind as or different from the resin material that forms thetire frame is wound in the circumferential direction of the tire frame.

By configuring the outer circumference of the tire frame to have thereinforcing layer formed by winding the coated cord member in thecircumferential direction of the tire frame as such, the rigidity of thetire frame in the circumferential direction may be enhanced.

(6-2-4) In the tire of the sixth aspect of the invention, athermoplastic resin material may be used as the resin material that is acomponent of the coated cord member.

By using the thermoplastic material having thermoplasticity as the resinmaterial that is a component of the coated cord member as such, comparedto a case of using a thermosetting material as the resin material, thetire is easily manufactured and is easily recycled.

(6-2-5) The tire of the sixth aspect of the invention may be configuredso that, in the roughening treatment step, an area wider than the areafor superposing the tire-constituting rubber member is subjected to theroughening treatment.

When the area wider than the area for superposing the tire-constitutingrubber member is subjected to the roughening treatment in the rougheningtreatment step, the bonding strength between the tire frame and thetire-constituting rubber member may be reliably ensured.

(6-2-6) The tire of the sixth aspect of the invention may be configuredso that, in the roughening treatment step, the outer circumferentialsurface is subjected to the roughening treatment to have an arithmeticmean roughness Ra of 0.05 mm or greater.

When the outer circumferential surface of the tire frame is subjected tothe roughening treatment to have an arithmetic mean roughness Ra of 0.05mm or greater in the roughening treatment step as such, in a case wherethe tire-constituting rubber member, for example, in an unvulcanized orsemi-vulcanized state is superposed on the outer circumferential surfacewhich has been subjected to the roughening treatment, via the bondingagent, and is vulcanized, rubber of the tire-constituting rubber membermay be caused to flow to the bottom of the roughened uneven portionformed by the roughening treatment. When the rubber of thetire-constituting rubber member flows to the bottom of the rougheneduneven portion, a sufficient anchor effect is exhibited between theouter circumferential surface and the tire-constituting rubber member,and the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

(6-2-7) In the tire of the sixth aspect of the invention, a rubber inthe unvulcanized or semi-vulcanized state may be used as thetire-constituting rubber member.

In the case where the rubber in the unvulcanized or semi-vulcanizedstate is used as the tire-constituting rubber member as such, the rubberflows to the roughened uneven portion formed on the outercircumferential surface of the tire frame by the roughening treatmentwhen the tire-constituting rubber member is vulcanized. In addition,when vulcanization is completed, the anchor effect is exhibited by the(vulcanized) rubber that has flowed to the roughened uneven portion, andthus the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

“Vulcanized” is referred to as a state in which the degree ofvulcanization reaches the degree needed for a final product, and the“semi-vulcanized state” is referred to as a state in which thevulcanization degree is higher than the unvulcanized state but has notreached the degree needed for a final product.”

(6-2-8) The tire of the sixth aspect of the invention may be configuredto include: a circular tire frame that is formed using the resinmaterial and has the outer circumferential surface which has beensubjected to the roughening treatment by allowing a particle-shapedblasting abrasive to collide with the outer circumferential surface; anda tire-constituting rubber member superposed on the outercircumferential surface which has been subjected to the rougheningtreatment, via the bonding agent.

When the circular tire frame subjected to the roughening treatment isused as such, the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced by the anchor effect. Inaddition, since the outer circumferential surface has been subjected tothe roughening treatment, excellent wettability of the bonding agent isprovided. Accordingly, the bonding agent is held in the state of beinguniformly applied onto the outer circumferential surface of the tireframe, the bonding strength between the tire frame and thetire-constituting rubber member is ensured, and thus peeling between thetire frame and the tire-constituting rubber member may be suppressed.

While the specific modes of the sixth aspect of the invention aredescribed using Embodiment 6-1 and Embodiment 6-2, the sixth aspect ofthe invention is not limited to the above-described modes.

The tire of the seventh aspect of the invention may be configured asfollows as described in Embodiment 7-1.

(7-1-1) The tire of the seventh aspect of the invention may beconfigured so that at least a part of the reinforcing cord member isembedded in the outer circumference of the tire frame formed of athermoplastic resin material in the present invention in the seventhaspect in the cross-sectional view along the axial direction of the tireframe.

When a part of the reinforcing cord member is embedded in the outercircumference of the tire frame as such, a phenomenon in which airremains in the area around the cord during winding of the reinforcingcord member (incorporation of air) may further be suppressed. Whenincorporation of air into the area around the reinforcing cord member issuppressed, movement of the reinforcing cord member due to, for example,a force applied during running is suppressed. Accordingly, for example,in the case where the tire-constituting member is provided on the outercircumference of the tire frame to cover the entire reinforcing cordmember, since the movement of the reinforcing cord member is suppressed,an occurrence of peeling and the like between the members (including thetire frame) is suppressed, and durability is enhanced.

(7-1-2) The tire of the seventh aspect of the invention may be providedwith a tread formed of a material having higher wear resistance than thethermoplastic resin material on the outer side in the radial directionof the reinforcing cord layer.

By having a configuration in which the tread that comes into contactwith the road surface is formed of the material having higher wearresistance than the thermoplastic resin material as such, the wearresistance of the tire may further be enhanced.

(7-1-3) In the tire of the seventh aspect of the invention, ⅕ or more ofthe diameter of the reinforcing cord member may be embedded in the outercircumference of the tire frame along the circumferential direction inthe cross-sectional view along the axial direction of the tire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord membermay be effectively suppressed, and thus movement of the reinforcing cordmember due to, for example, a force applied during running may furtherbe suppressed.

(7-1-4) The tire of the seventh aspect of the invention may beconfigured so that the tire frame includes, on the inner side in theradial direction, a bead portion that comes into contact with a beadseat and a rim flange of a rim, and an annular bead core made of a metalmaterial is embedded in the bead portion.

By providing the bead portion which is a part for fitting onto the rimin the tire frame, and moreover, by embedding the annular bead core madeof the metal material in the bead portion as such, the tire frame (thatis, tire) may be firmly held on the rim, similarly to conventionalpneumatic tires made of rubber.

(7-1-5) The tire of the seventh aspect of the invention may be providedwith a sealing portion made of a material having higher sealingproperties (adhesion to the rim) than the thermoplastic resin material,in a part where the bead portion comes into contact with the rim.

By providing the sealing portion made of the material having highersealing properties than the thermoplastic resin material in the partwhere the tire frame and the rim come into contact with each other assuch, adhesion between the tire (the tire frame) and the rim may beenhanced. Accordingly, compared to a case where only the rim and thethermoplastic resin material are used, leakage of air in the tire mayfurther be suppressed. In addition, by providing the sealing portion,fittability onto the rim of the tire may be enhanced.

(7-1-6) The manufacturing method of the tire of the seventh aspect ofthe invention may include: a tire frame piece forming step of forming atire frame pieces for constituting a part of the circular tire frameusing a thermoplastic resin material that includes a mixed material ofat least a polyamide-based thermoplastic elastomer (for example,“UBESTA, XPA9055X1” made by Ube Industries, Ltd.) and a polyamide-basedthermoplastic resin (for example, “UBESTA, 3014U” made by UbeIndustries, Ltd.); a tire frame piece bonding step of forming a tireframe by fusing two or more tire frame pieces, which make a pair, byapplying heat to the bonding surfaces of the tire frame pieces; and areinforcing cord member winding step of winding a reinforcing cordmember around the outer circumference of the tire frame in thecircumferential direction to form the reinforcing cord layer.

(7-1-7) The manufacturing method of the tire may be configured so that,in the tire frame piece bonding step, the bonding surface of the tireframe piece is heated to a temperature equal to or higher than themelting point of the thermoplastic resin material that forms the tireframe piece.

When the bonding surface of the divided body is heated to a temperatureequal to or higher than the melting point of the thermoplastic resinmaterial that forms the tire frame piece as such, fusing between thetire frame pieces may be sufficiently performed. Therefore, productivityof the tire may be enhanced while enhancing durability of the tire.

(7-1-8) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, the reinforcing cord memberis wound around the outer circumference of the tire frame in a mannersuch that at least a part of the reinforcing cord member is embeddedwhile melting or softening the outer circumference of the tire frameformed in the tire frame piece bonding step.

By winding the reinforcing cord member around the outer circumference ofthe tire frame in a manner such that at least a part of the reinforcingcord member is embedded while melting and softening the outercircumference of the tire frame as such, at least the part of thereinforcing cord member which is embedded and the melted or softenedthermoplastic resin material may be welded. Accordingly, incorporationof air between the outer circumference of the tire frame and thereinforcing cord member in the cross-sectional view along the axialdirection of the tire frame may further be suppressed. In addition, whenthe part in which the reinforcing cord member is embedded is cooled andsolidified, the fixed condition of the reinforcing cord member embeddedin the tire frame is enhanced.

(7-1-9) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, ⅕ or more of the diameterof the reinforcing cord may be embedded in the outer circumference ofthe tire frame in the cross-sectional view along the axial direction ofthe tire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord duringmanufacturing may be effectively suppressed, and moreover, the embeddedreinforcing cord member may become less likely to be caused to come outof the tire frame.

(7-1-10) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, the heated reinforcing cordmember is embedded in the tire frame.

By embedding the reinforcing cord member in the tire frame while heatingthe reinforcing cord member in the reinforcing cord winding step assuch, when the heated reinforcing cord member comes into contact withthe outer circumference of the tire frame, the contact part is melted orsoftened. Therefore, it becomes easy to embed the reinforcing cordmember in the outer circumference of the tire frame.

(7-1-11) The manufacturing method of the tire may be configured so that,in the cord member winding step, the part of the outer circumference ofthe tire frame for embedding the reinforcing cord member is heated.

By heating the part of the outer circumference of the tire frame forembedding the reinforcing cord member as such, the heated part of thetire frame is melted or softened. Therefore, it becomes easy to embedthe reinforcing cord member.

(7-1-12) The manufacturing method of the tire may be configured so that,in the cord member winding step, the reinforcing cord member is wound ina spiral shape in the circumferential direction of the outercircumference of the tire frame while pressing the reinforcing cordmember against the outer circumference of the tire frame.

When the reinforcing cord member is wound in the spiral shape whilepressing the reinforcing cord member against the outer circumference ofthe tire frame as such, the depth of embedding the reinforcing cordmember in the outer circumference of the tire frame may be adjusted.

(7-1-13) According to the manufacturing method, it may be configuredsuch that, in the cord member winding step, after winding thereinforcing cord member around the tire frame, the melted or softenedpart of the outer circumference of the tire frame is cooled.

By forcibly cooling the melted or softened part of the outercircumference of the tire frame after embedding the reinforcing cordmember as such, the melted or softened part of the outer circumferenceof the tire frame may be more quickly and rapidly cooled and solidifiedthan natural cooling. By cooling the outer circumference of the tiremore quickly than natural cooling, deformation of the outercircumference of the tire frame may be suppressed, and movement of thereinforcing cord member may be suppressed.

The tire of the seventh aspect of the invention may be configured asfollows as described in Embodiment 7-2.

(7-2-1) The tire of the seventh aspect of the invention may beconfigured so that the manufacturing method further includes: aroughening treatment step of performing the roughening treatment on theouter circumferential surface of the tire frame by allowing aparticle-shaped blasting abrasive to collide with the outercircumferential surface of the tire frame; and a superposing step ofsuperposing a tire-constituting rubber member on the outercircumferential surface which has been subjected to the rougheningtreatment, via a bonding agent.

When the roughening treatment step is provided as such, theparticle-shaped blasting abrasive collides with the outercircumferential surface of the circular tire frame formed using athermoplastic resin material, and thus minute roughened unevenness isformed on the outer circumferential surface. The treatment of formingminute roughened unevenness by allowing the blasting abrasive to collidewith the outer circumferential surface of the tire frame is referred toas the roughening treatment. Thereafter, the tire-constituting rubbermember is superposed on the outer circumferential surface which has beensubjected to the roughening treatment, via the bonding agent. Here, whenthe tire frame and the tire-constituting rubber member are integratedinto each other, since the outer circumferential surface of the tireframe has been subjected to the roughening treatment, bonding properties(adhesiveness) are enhanced due to the anchor effect. In addition, sincethe resin material that forms the tire frame is ploughed due tocollision of the blasting abrasive, wettability of the outercircumferential surface is enhanced. Accordingly, the outercircumferential surface of the tire frame is held in a state of beinguniformly coated with the bonding agent, and thus the bonding strengthbetween the tire frame and the tire-constituting rubber member may beensured.

(7-2-2) In the tire of the seventh aspect of the invention, at least apart of the outer circumferential surface of the tire frame may be anuneven portion, and the uneven portion may be subjected to theroughening treatment in the roughening treatment step.

Even if at least a part of the outer circumferential surface of the tireframe is the uneven portion as such, by allowing the blasting abrasiveto collide with the uneven portion, the area around a recess (walls atthe recess, the bottom of the recess) is subjected to the rougheningtreatment, and thus the bonding strength between the tire frame and thetire-constituting rubber member may be ensured.

(7-2-3) In the tire of the seventh aspect of the invention, the outercircumference of the tire frame is configured to have a reinforcinglayer that constitutes the uneven portion at the outer circumferentialsurface, and the reinforcing layer may be configured such that a coatedcord member formed by coating a reinforcing cord with a resin materialof the same kind as or different from the resin material that forms thetire frame, is wound in the circumferential direction of the tire frame.

By configuring the outer circumference of the tire frame to have thereinforcing layer formed by winding the coated cord member in thecircumferential direction of the tire frame as such, the rigidity of thetire frame in the circumferential direction may be enhanced.

(7-2-4) In the tire of the seventh aspect of the invention, athermoplastic resin material may be used as the resin material that is acomponent of the coated cord member.

By using the thermoplastic material having thermoplasticity as the resinmaterial that is a component of the coated cord member as such, comparedto a case of using a thermosetting material as the resin material, thetire is easily manufactured and is easily recycled.

(7-2-5) The tire of the seventh aspect of the invention may beconfigured so that, in the roughening treatment step, an area wider thanthe area for superposing the tire-constituting rubber member issubjected to the roughening treatment.

When the area wider than the area for superposing the tire-constitutingrubber member is subjected to the roughening treatment in the rougheningtreatment step, the bonding strength between the tire frame and thetire-constituting rubber member may be reliably ensured.

(7-2-6) The tire of the seventh aspect of the invention may beconfigured so that, in the roughening treatment step, the outercircumferential surface is subjected to the roughening treatment to havean arithmetic mean roughness Ra of 0.05 mm or greater.

When the outer circumferential surface of the tire frame is subjected tothe roughening treatment to have an arithmetic mean roughness Ra of 0.05mm or greater in the roughening treatment step as such, in a case wherethe tire-constituting rubber member, for example, in an unvulcanized orsemi-vulcanized state is superposed on the outer circumferential surfacewhich has been subjected to the roughening treatment, via the bondingagent, and is vulcanized, rubber of the tire-constituting rubber membermay be caused to flow to the bottom of the roughened uneven portionformed by the roughening treatment. When the rubber of thetire-constituting rubber member flows to the bottom of the rougheneduneven portion, a sufficient anchor effect is exhibited between theouter circumferential surface and the tire-constituting rubber member,and the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

(7-2-7) In the tire of the seventh aspect of the invention, a rubber inthe unvulcanized or semi-vulcanized state may be used as thetire-constituting rubber member.

In the case where the rubber in the unvulcanized or semi-vulcanizedstate is used as the tire-constituting rubber member as such, the rubberflows to the roughened uneven portion formed on the outercircumferential surface of the tire frame by the roughening treatmentwhen the tire-constituting rubber member is vulcanized. In addition,when vulcanization is completed, the anchor effect is exhibited by the(vulcanized) rubber that has flowed to the roughened uneven portion, andthus the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

“Vulcanized” is referred to as a state in which the degree ofvulcanization reaches the degree needed for a final product, and the“semi-vulcanized state” is referred to as a state in which thevulcanization degree is higher than the unvulcanized state but has notreached the degree needed for a final product.

(7-2-8) The tire of the seventh aspect of the invention may beconfigured to include: a circular tire frame that is formed using thethermoplastic resin material in the seventh aspect of the presentinvention and has the outer circumferential surface which has beensubjected to the roughening treatment by allowing a particle-shapedblasting abrasive to collide with the outer circumferential surface; anda tire-constituting rubber member superposed on the outercircumferential surface which has been subjected to the rougheningtreatment, via a bonding agent.

When the circular tire frame which has been subjected to the rougheningtreatment is used as such, the bonding strength between the tire frameand the tire-constituting rubber member may be enhanced by the anchoreffect. In addition, since the outer circumferential surface has beensubjected to the roughening treatment, excellent wettability of thebonding agent is provided. Accordingly, the bonding agent is held in thestate of being uniformly applied onto the outer circumferential surfaceof the tire frame, the bonding strength between the tire frame and thetire-constituting rubber member is ensured, and thus peeling between thetire frame and the tire-constituting rubber member may be suppressed.

The tire of the eighth aspect of the invention may be configured asfollows as described in Embodiment 8-1.

(8-1-1) The tire of the eighth aspect of the invention may be configuredso that at least a part of the reinforcing cord member is embedded inthe outer circumference of the tire frame formed of the thermoplasticresin material in the cross-sectional view along the axial direction ofthe tire frame.

When a part of the reinforcing cord member is embedded in the outercircumference of the tire frame as such, a phenomenon in which airremains in the area around the cord during winding of the reinforcingcord member (incorporation of air) may further be suppressed. Whenincorporation of air into the area around the reinforcing cord member issuppressed, movement of the reinforcing cord member due to, for example,a force applied during running is suppressed. Accordingly, for example,in the case where the tire-constituting member is provided in the outercircumference of the tire frame to cover the entire reinforcing cordmember, since the movement of the reinforcing cord member is suppressed,an occurrence of peeling and the like between the members (including thetire frame) is suppressed, and durability is enhanced.

(8-1-2) The tire of the eighth aspect of the invention may be providedwith a tread formed of a material having higher wear resistance than thethermoplastic resin material on the outer side in the radial directionof the reinforcing cord layer.

By having a configuration in which the tread that comes into contactwith the road surface is formed of the material having higher wearresistance than the thermoplastic resin material as such, the wearresistance of the tire may further be enhanced.

(8-1-3) In the tire of the eighth aspect of the invention, ⅕ or more ofthe diameter of the reinforcing cord member may be embedded in the outercircumference of the tire frame along the circumferential direction inthe cross-sectional view along the axial direction of the tire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord membermay be effectively suppressed, and thus movement of the reinforcing cordmember due to, for example, a force applied during running may furtherbe suppressed.

(8-1-4) The tire of the eighth aspect of the invention may be configuredso that the tire frame includes, on the inner side in the radialdirection, a bead portion that comes into contact with a bead seat and arim flange of a rim, and an annular bead core made of a metal materialis embedded in the bead portion.

By providing the bead portion which is a part for fitting onto the rimin the tire frame, and moreover, by embedding the annular bead core madeof a metal material in the bead portion as such, the tire frame (thatis, tire) may be firmly held on the rim, similarly to conventionalpneumatic tires made of rubber.

(8-1-5) The tire of the eighth aspect of the invention may be providedwith a sealing portion made of a material having higher sealingproperties (adhesion to the rim) than the thermoplastic resin material,in a part where the bead portion comes into contact with the rim.

By providing the sealing portion made of the material having highersealing properties than the thermoplastic resin material in the partwhere the tire frame and the rim come into contact with each other assuch, adhesion between the tire (the tire frame) and the rim may beenhanced. Accordingly, compared to a case where only the rim and thethermoplastic resin material are used, leakage of air in the tire mayfurther be suppressed. In addition, by providing the sealing portion,fittability onto the rim of the tire may be enhanced.

(8-1-6) The tire of the eighth aspect of the invention may bemanufactured according to a manufacturing method that includes: a tireframe piece forming step of forming a tire frame piece for constitutinga part of the circular tire frame using at least a resin material; atire frame piece bonding step of forming a tire by fusing two or moretire frame pieces, which make a pair, by applying heat to the bondingsurfaces of the tire frame pieces; and a reinforcing cord member windingstep of winding a reinforcing cord layer around the outer circumferenceof the tire frame in the circumferential direction to form a reinforcingcord layer.

(8-1-7) The manufacturing method of the tire may be configured so that,in the tire frame piece bonding step, the bonding surface of the tireframe piece is heated to a temperature equal to or higher than themelting point (for example, the melting point +10° C. to +150° C.) ofthe thermoplastic resin material that forms the tire frame piece.

When the bonding surface of the divided body is heated to a temperatureequal to or higher than the melting point of the thermoplastic resinmaterial that forms the tire frame piece as such, fusing between thetire frame pieces may be sufficiently performed. Therefore, productivityof the tire may be enhanced while enhancing durability of the tire.

(8-1-8) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, the reinforcing cord memberis wound around the outer circumference of the tire frame in a mannersuch that at least a part of the reinforcing cord member is embeddedwhile melting or softening the outer circumference of the tire frameformed in the tire frame piece bonding step.

By winding the reinforcing cord member around the outer circumference ofthe tire frame in a manner such that at least a part of the reinforcingcord member is embedded while melting and softening the outercircumference of the tire frame as such, the at least a part of thereinforcing cord member which is embedded and the melted or softenedthermoplastic resin material may be welded. Accordingly, incorporationof air between the outer circumference of the tire frame and thereinforcing cord member in the cross-sectional view along the axialdirection of the tire frame may further be suppressed. In addition, whenthe part in which the reinforcing cord member is embedded is cooled andsolidified, the fixed condition of the reinforcing cord member embeddedin the tire frame is enhanced.

(8-1-9) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, ⅕ or more of the diameterof the reinforcing cord may be embedded in the outer circumference ofthe tire frame in the cross-sectional view along the axial direction ofthe tire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord duringmanufacturing may be effectively suppressed, and moreover, the embeddedreinforcing cord member may become less likely to be caused to come outof the tire frame.

(8-1-10) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, the heated reinforcing cordmember is embedded in the tire frame.

By embedding the reinforcing cord member in the tire frame while heatingthe reinforcing cord member in the reinforcing cord winding step assuch, when the heated reinforcing cord member comes into contact withthe outer circumference of the tire frame, the contact part is melted orsoftened. Therefore, it becomes easy to embed the reinforcing cordmember in the outer circumference of the tire frame.

(8-1-11) The manufacturing method of the tire may be configured so that,in the cord member winding step, the part of the outer circumference ofthe tire frame for embedding the reinforcing cord member is heated.

By heating the part of the outer circumference of the tire frame forembedding the reinforcing cord member as such, the heated part of thetire frame is melted or softened. Therefore, it becomes easy to embedthe reinforcing cord member.

(8-1-12) The manufacturing method of the tire may be configured so that,in the cord member winding step, the reinforcing cord member is wound ina spiral shape in the circumferential direction of the outercircumference of the tire frame while adjusting the tension of thereinforcing cord member to be a predetermined value.

By winding the reinforcing cord member in the spiral shape around theouter circumference of the tire frame while adjusting the tension of thereinforcing cord member to be a predetermined value as such, the depthof embedding the reinforcing cord member in the outer circumference ofthe tire frame may be adjusted, and moreover, meandering of thereinforcing cord member during winding thereof may be suppressed.

(8-1-13) The manufacturing method of the tire may be configured so that,in the cord member winding step, the reinforcing cord member is wound ina spiral shape in the circumferential direction of the outercircumference of the tire frame while pressing the reinforcing cordmember against the outer circumference of the tire frame.

When the reinforcing cord member is wound in the spiral shape whilepressing the reinforcing cord member against the outer circumference ofthe tire frame as such, the depth of embedding the reinforcing cordmember in the outer circumference of the tire frame may be adjusted.

(8-1-14) According to the manufacturing method, it may be configuredsuch that, in the cord member winding step, after winding thereinforcing cord member around the tire frame, the melted or softenedpart of the outer circumference of the tire frame is cooled.

By forcibly cooling the melted or softened part of the outercircumference of the tire frame after embedding the reinforcing cordmember as such, the melted or softened part of the outer circumferenceof the tire frame may be more quickly and rapidly cooled and solidifiedthan natural cooling. By cooling the outer circumference of the tiremore quickly than natural cooling, deformation of the outercircumference of the tire frame may be suppressed, and movement of thereinforcing cord member may be suppressed.

The tire of the eighth aspect of the invention may be configured asfollows as described in Embodiment 8-2.

(8-2-1) The tire of the eighth aspect of the invention may be configuredsuch that the manufacturing method further includes: a rougheningtreatment step of performing the roughening treatment on the outercircumferential surface of the tire frame by allowing a particle-shapedblasting abrasive to collide with the outer circumferential surface ofthe tire frame; and a superposing step of superposing atire-constituting rubber member on the outer circumferential surfacewhich has been subjected to the roughening treatment, via a bondingagent.

When the roughening treatment step is provided as such, theparticle-shaped blasting abrasive collides with the outercircumferential surface of the circular tire frame formed by using theresin material, and thus minute roughened unevenness is formed on theouter circumferential surface. The treatment of forming minute roughenedunevenness by allowing the blasting abrasive to collide with the outercircumferential surface of the tire frame is referred to as theroughening treatment. Thereafter, the tire-constituting rubber member issuperposed on the outer circumferential surface which has been subjectedto the roughening treatment, via the bonding agent. Here, when the tireframe and the tire-constituting rubber member are integrated into eachother, since the outer circumferential surface of the tire frame hasbeen subjected to the roughening treatment, bonding properties(adhesiveness) are enhanced due to the anchor effect. In addition, sincethe resin material that forms the tire frame is ploughed due tocollision of the blasting abrasive, wettability of the outercircumferential surface is enhanced. Accordingly, the outercircumferential surface of the tire frame is held in a state of beinguniformly coated with the bonding agent, and thus the bonding strengthbetween the tire frame and the tire-constituting rubber member may beensured.

(8-2-2) In the tire of the eighth aspect of the invention, at least apart of the outer circumferential surface of the tire frame may be anuneven portion, and the uneven portion may be subjected to theroughening treatment in the roughening treatment step.

Even if at least a part of the outer circumferential surface of the tireframe is the uneven portion as such, by allowing the blasting abrasiveto collide with the uneven portion, the area around a recess (walls atthe recess, the bottom of the recess) is subjected to the rougheningtreatment, and thus the bonding strength between the tire frame and thetire-constituting rubber member may be ensured.

(8-2-3) In the tire of the eighth aspect of the invention, the outercircumference of the tire frame is configured to have a reinforcinglayer that constitutes the uneven portion at the outer circumferentialsurface, and the reinforcing layer may be configured such that a coatedcord member formed by coating the reinforcing cord with a resin materialof the same kind as or different from the resin material that forms thetire frame is wound in the circumferential direction of the tire frame.

By configuring the outer circumference of the tire frame to have thereinforcing layer formed by winding the coated cord member in thecircumferential direction of the tire frame as such, the rigidity of thetire frame in the circumferential direction may be enhanced.

(8-2-4) In the tire of the eighth aspect of the invention, athermoplastic resin material may be used as the resin material that is acomponent of the coated cord member.

By using the thermoplastic material having thermoplasticity as the resinmaterial that is a component of the coated cord member as such, comparedto a case of using a thermosetting material as the resin material, thetire is easily manufactured and is easily recycled.

(8-2-5) The tire of the eighth aspect of the invention may be configuredso that, in the roughening treatment step, an area wider than the areafor superposing the tire-constituting rubber member is subjected to theroughening treatment.

When the area wider than the area for superposing the tire-constitutingrubber member is subjected to the roughening treatment in the rougheningtreatment step, the bonding strength between the tire frame and thetire-constituting rubber member may be reliably ensured.

(8-2-6) The tire of the eighth aspect of the invention may be configuredso that, in the roughening treatment step, the outer circumferentialsurface is subjected to the roughening treatment to have an arithmeticmean roughness Ra of 0.05 mm or greater.

When the outer circumferential surface of the tire frame is subjected tothe roughening treatment to have an arithmetic mean roughness Ra of 0.05mm or greater in the roughening treatment step as such, in a case wherethe tire-constituting rubber member, for example, in an unvulcanized orsemi-vulcanized state is superposed on the outer circumferential surfacewhich has been subjected to the roughening treatment, via the bondingagent, and is vulcanized, rubber of the tire-constituting rubber membermay be caused to flow to the bottom of the roughened uneven portionformed by the roughening treatment. When the rubber of thetire-constituting rubber member flows to the bottom of the rougheneduneven portion, a sufficient anchor effect is exhibited between theouter circumferential surface and the tire-constituting rubber member,and the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

(8-2-7) In the tire of the eighth aspect of the invention, the blastingabrasive may be configured to use a material that is vaporized into agas from a solid in the air.

When the material that is vaporized into a gas from a solid in the airis used as the blasting abrasive, after the roughening treatment of theouter circumferential surface of the tire frame, the blasting abrasiveis vaporized into a gas from a solid in the air, and thus the blastingabrasive does not remain on the outer circumferential surface of thetire frame. Accordingly, an operation of removing the blasting abrasivethat remains on the outer circumferential surface of the tire frame, andthe like are not necessary, and complexity of the operation may beimproved.

(8-2-8) In the tire of the eighth aspect of the invention, a rubber inthe unvulcanized or semi-vulcanized state may be used as thetire-constituting rubber member.

In the case where the rubber in the unvulcanized or semi-vulcanizedstate is used as the tire-constituting rubber member as such, the rubberflows to the roughened uneven portion formed on the outercircumferential surface of the tire frame by the roughening treatmentwhen the tire-constituting rubber member is vulcanized. In addition,when vulcanization is completed, the anchor effect is exhibited by the(vulcanized) rubber that has flowed to the roughened uneven portion, andthus the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

“Vulcanized” is referred to as a state in which the degree ofvulcanization reaches the degree needed for a final product, and the“semi-vulcanized state” is referred to as a state in which thevulcanization degree is higher than the unvulcanized state but has notreached the degree needed for a final product.

(8-2-9) The tire of the eighth aspect of the invention may be configuredto include: a circular tire frame that is formed using a resin materialand has the outer circumferential surface which has been subjected tothe roughening treatment by allowing a particle-shaped blasting abrasiveto collide with the outer circumferential surface; and atire-constituting rubber member superposed on the outer circumferentialsurface which has been subjected to the roughening treatment, via thebonding agent.

When the circular tire frame which has been subjected to the rougheningtreatment is used as such, the bonding strength between the tire frameand the tire-constituting rubber member may be enhanced by the anchoreffect. In addition, since the outer circumferential surface has beensubjected to the roughening treatment, excellent wettability of thebonding agent is provided. Accordingly, the bonding agent is held in thestate of being uniformly applied onto the outer circumferential surfaceof the tire frame, the bonding strength between the tire frame and thetire-constituting rubber member is ensured, and thus peeling between thetire frame and the tire-constituting rubber member may be suppressed.

The tire of the ninth aspect of the invention may be configured asfollows as described in Embodiment 9-1.

(9-1-1) The tire of the ninth aspect of the invention may be configuredso that at least a part of the reinforcing cord member is embedded inthe outer circumference of the tire frame formed of the thermoplasticresin material in the cross-sectional view along the axial direction ofthe tire frame.

When a part of the reinforcing cord member is embedded in the outercircumference of the tire frame as such, a phenomenon in which airremains in the area around the cord during winding of the reinforcingcord member (incorporation of air) may further be suppressed. Whenincorporation of air into the area around the reinforcing cord member issuppressed, movement of the reinforcing cord member due to, for example,a force applied during running is suppressed. Accordingly, for example,in the case where the tire-constituting member is provided on the outercircumference of the tire frame to cover the entire reinforcing cordmember, since the movement of the reinforcing cord member is suppressed,an occurrence of peeling and the like between the members (including thetire frame) is suppressed, and durability is enhanced.

(9-1-2) The tire of the ninth aspect of the invention may be providedwith a tread formed of a material having higher wear resistance than thethermoplastic resin material, on the outer side in the radial directionof the reinforcing cord layer.

By having a configuration in which the tread that comes into contactwith the road surface is formed of the material having higher wearresistance than the thermoplastic resin material as such, the wearresistance of the tire may further be enhanced.

(9-1-3) In the tire of the ninth aspect of the invention, ⅕ or more ofthe diameter of the reinforcing cord member may be embedded in the outercircumference of the tire frame along the circumferential direction inthe cross-sectional view along the axial direction of the tire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord membermay be effectively suppressed, and thus movement of the reinforcing cordmember due to, for example, a force applied during running may furtherbe suppressed.

(9-1-4) The tire of the ninth aspect of the invention may be configuredso that the tire frame includes, on the inner side in the radialdirection, a bead portion that comes into contact with a bead seat and arim flange of a rim, and an annular bead core made of a metal materialis embedded in the bead portion.

By providing the bead portion which is a part for fitting onto the rimin the tire frame, and moreover, by embedding the annular bead core madeof the metal material in the bead portion as such, the tire frame (thatis, tire) may be firmly held on the rim, similarly to conventionalpneumatic tires made of rubber.

(9-1-5) The tire of the ninth aspect of the invention may be providedwith a sealing portion made of a material having higher sealingproperties (adhesion to the rim) than the thermoplastic resin material,in a part where the bead portion comes into contact with the rim.

By providing the sealing portion made of the material having highersealing properties than the thermoplastic resin material in the partwhere the tire frame and the rim come into contact with each other assuch, adhesion between the tire (the tire frame) and the rim may beenhanced. Accordingly, compared to a case where only the rim and thethermoplastic resin material are used, leakage of air in the tire mayfurther be suppressed. In addition, by providing the sealing portion,fittability onto the rim of the tire may be enhanced.

(9-1-6) The tire of the ninth aspect of the invention may bemanufactured according to a manufacturing method that includes: a tireframe piece forming step of forming a tire frame piece for constitutinga part of the circular tire frame using at least a resin material; thetire frame piece bonding step of forming a tire frame by fusing two ormore tire frame pieces, which make a pair, by applying heat to thebonding surfaces of the tire frame pieces to form the tire frame; and areinforcing cord member winding step of winding a reinforcing cordmember around the outer circumference of the tire frame in thecircumferential direction to form a reinforcing cord layer.

(9-1-7) The manufacturing method of the tire may be configured so that,in the tire frame piece bonding step, the bonding surface of the tireframe piece is heated to a temperature equal to or higher than themelting point (for example, the melting point +10° C. to +150° C.) ofthe thermoplastic resin material that forms the tire frame piece.

When the bonding surface of the divided body is heated to a temperatureequal to or higher than the melting point of the thermoplastic resinmaterial that forms the tire frame piece as such, fusing between thetire frame pieces may be sufficiently performed. Therefore, productivityof the tire may be enhanced while enhancing durability of the tire.

(9-1-8) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, the reinforcing cord memberis wound around the outer circumference of the tire frame in a mannersuch that at least a part of the reinforcing cord member is embeddedwhile melting or softening the outer circumference of the tire frameformed in the tire frame piece bonding step.

By winding the reinforcing cord member around the outer circumference ofthe tire frame in manner such that at least a part of the reinforcingcord member is embedded while melting and softening the outercircumference of the tire frame as such, the at least a part of thereinforcing cord member which is embedded and the melted or softenedthermoplastic resin material may be welded. Accordingly, incorporationof air between the outer circumference of the tire frame and thereinforcing cord member in the cross-sectional view along the axialdirection of the tire frame may further be suppressed. In addition, whenthe part in which the reinforcing cord member is embedded is cooled andsolidified, the fixed condition of the reinforcing cord member embeddedin the tire frame is enhanced.

(9-1-9) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, ⅕ or more of the diameterof the reinforcing cord may be embedded in the outer circumference ofthe tire frame in the cross-sectional view along the axial direction ofthe tire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord duringmanufacturing may be effectively suppressed, and moreover, the embeddedreinforcing cord member may become less likely to be caused to come outof the tire frame.

(9-1-10) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, the heated reinforcing cordmember is embedded in the tire frame.

By embedding the reinforcing cord member in the tire frame while heatingthe reinforcing cord member in the reinforcing cord winding step assuch, when the heated reinforcing cord member comes into contact withthe outer circumference of the tire frame, the contact part is melted orsoftened. Therefore, it becomes easy to embed the reinforcing cordmember in the outer circumference of the tire frame.

(9-1-11) The manufacturing method of the tire may be configured so that,in the cord member winding step, the part of the outer circumference ofthe tire frame for embedding the reinforcing cord member is heated.

By heating the part of the outer circumference of the tire frame forembedding the reinforcing cord member as such, the heated part of thetire frame is melted or softened. Therefore, it becomes easy to embedthe reinforcing cord member.

(9-1-12) The manufacturing method of the tire may be configured so that,in the cord member winding step, the reinforcing cord member is wound ina spiral shape in the circumferential direction of the outercircumference of the tire frame while adjusting the tension of thereinforcing cord member to be a predetermined value.

By winding the reinforcing cord member in the spiral shape around theouter circumference of the tire frame while adjusting the tension of thereinforcing cord member to be a predetermined value as such, the depthof embedding the reinforcing cord member in the outer circumference ofthe tire frame may be adjusted, and moreover, meandering of thereinforcing cord member during winding thereof may be suppressed.

(9-1-13) The manufacturing method of the tire may be configured so that,in the cord member winding step, the reinforcing cord member is wound ina spiral shape in the circumferential direction of the outercircumference of the tire frame while pressing the reinforcing cordmember against the outer circumference of the tire frame.

When the reinforcing cord member is wound in the spiral shape whilepressing the reinforcing cord member against the outer circumference ofthe tire frame as such, the depth of embedding the reinforcing cordmember in the outer circumference of the tire frame may be adjusted.

(9-1-14) According to the manufacturing method, it may be configuredsuch that, in the cord member winding step, after winding thereinforcing cord member around the tire frame, the melted or softenedpart of the outer circumference of the tire frame is cooled.

By forcibly cooling the melted or softened part of the outercircumference of the tire frame after embedding the reinforcing cordmember as such, the melted or softened part of the outer circumferenceof the tire frame may be more quickly and rapidly cooled and solidifiedthan natural cooling. By cooling the outer circumference of the tiremore quickly than natural cooling, deformation of the outercircumference of the tire frame may be suppressed, and movement of thereinforcing cord member may be suppressed.

The tire of the ninth aspect of the invention may be configured asfollows as described in Embodiment 9-2.

(9-2-1) The tire of the ninth aspect of the invention may be configuredsuch that the manufacturing method further includes: a rougheningtreatment step of performing the roughening treatment on the outercircumferential surface of the tire frame by allowing a particle-shapedblasting abrasive to collide with the outer circumferential surface ofthe tire frame; and a superposing step of superposing atire-constituting rubber member on the outer circumferential surfacewhich has been subjected to the roughening treatment, via a bondingagent.

When the roughening treatment step is provided as such, theparticle-shaped blasting abrasive collides with the outercircumferential surface of the circular tire frame formed using theresin material, and thus minute roughened unevenness is formed on theouter circumferential surface. The treatment of forming minute roughenedunevenness by allowing the blasting abrasive to collide with the outercircumferential surface of the tire frame is referred to as theroughening treatment. Thereafter, the tire-constituting rubber member issuperposed on the outer circumferential surface which has been subjectedto the roughening treatment, via the bonding agent. Here, when the tireframe and the tire-constituting rubber member are integrated into eachother, since the outer circumferential surface of the tire frame hasbeen subjected to the roughening treatment, bonding properties (bondingproperties) are enhanced due to the anchor effect. In addition, sincethe resin material that forms the tire frame is ploughed due tocollision of the blasting abrasive, wettability of the outercircumferential surface is enhanced. Accordingly, the outercircumferential surface of the tire frame is held in a state of beinguniformly coated with the bonding agent, and thus the bonding strengthbetween the tire frame and the tire-constituting rubber member may beensured.

(9-2-2) In the tire of the ninth aspect of the invention, at least apart of the outer circumferential surface of the tire frame may be anuneven portion, and the uneven portion may be subjected to theroughening treatment in the roughening treatment step.

Even if at least a part of the outer circumferential surface of the tireframe is the uneven portion as such, by allowing the blasting abrasiveto collide with the uneven portion, the area around a recess (walls atthe recess, the bottom of the recess) is subjected to the rougheningtreatment, and thus the bonding strength between the tire frame and thetire-constituting rubber member may be ensured.

(9-2-3) In the tire of the ninth aspect of the invention, the outercircumference of the tire frame is configured to have a reinforcinglayer that constitutes the uneven portion at the outer circumferentialsurface, and the reinforcing layer may be configured such that a coatedcord member formed by coating the reinforcing cord with a resin materialof the same kind as or different from the resin material that forms thetire frame is wound in the circumferential direction of the tire frame.

By configuring the outer circumference of the tire frame to have thereinforcing layer formed by winding the coated cord member in thecircumferential direction of the tire frame as such, the rigidity of thetire frame in the circumferential direction may be enhanced.

(9-2-4) In the tire of the ninth aspect of the invention, athermoplastic resin material may be used as the resin material that is acomponent of the coated cord member.

By using the thermoplastic material having thermoplasticity as the resinmaterial that is a component of the coated cord member as such, comparedto a case of using a thermosetting material as the resin material, thetire is easily manufactured and is easily recycled.

(9-2-5) The tire of the ninth aspect of the invention may be configuredso that, in the roughening treatment step, an area wider than the areafor superposing the tire-constituting rubber member is subjected to theroughening treatment.

When the area wider than the area for superposing the tire-constitutingrubber member is subjected to the roughening treatment in the rougheningtreatment step, the bonding strength between the tire frame and thetire-constituting rubber member may be reliably ensured.

(9-2-6) The tire of the ninth aspect of the invention may be configuredso that, in the roughening treatment step, the outer circumferentialsurface is subjected to the roughening treatment to have an arithmeticmean roughness Ra of 0.05 mm or greater.

When the outer circumferential surface of the tire frame is subjected tothe roughening treatment to have an arithmetic mean roughness Ra of 0.05mm or greater in the roughening treatment step as such, in a case wherethe tire-constituting rubber member, for example, in an unvulcanized orsemi-vulcanized state is superposed on the outer circumferential surfacewhich has been subjected to the roughening treatment, via the bondingagent, and is vulcanized, rubber of the tire-constituting rubber membermay be caused to flow to the bottom of the roughened uneven portionformed by the roughening treatment. When the rubber of thetire-constituting rubber member flows to the bottom of the rougheneduneven portion, a sufficient anchor effect is exhibited between theouter circumferential surface and the tire-constituting rubber member,and the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

(9-2-7) In the tire of the ninth aspect of the invention, the blastingabrasive may be configured to use a material that is vaporized into agas from a solid in the air.

When the material that is vaporized into a gas from a solid in the airis used as the blasting abrasive, after the roughening treatment of theouter circumferential surface of the tire frame, the blasting abrasiveis vaporized into a gas from a solid in the air, and thus the blastingabrasive does not remain on the outer circumferential surface of thetire frame. Accordingly, an operation of removing the blasting abrasivethat remains on the outer circumferential surface of the tire frame, andthe like are not necessary, and complexity of the operation may beimproved.

(9-2-8) In the tire of the ninth aspect of the invention, a rubber inthe unvulcanized or semi-vulcanized state may be used as thetire-constituting rubber member.

In the case where the rubber in the unvulcanized or semi-vulcanizedstate is used as the tire-constituting rubber member as such, the rubberflows to the roughened uneven portion formed on the outercircumferential surface of the tire frame by the roughening treatmentwhen the tire-constituting rubber member is vulcanized. In addition,when vulcanization is completed, the anchor effect is exhibited by the(vulcanized) rubber that has flowed to the roughened uneven portion, andthus the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

“Vulcanized” is referred to as a state in which the degree ofvulcanization reaches the degree needed for a final product, and the“semi-vulcanized state” is referred to as a state in which thevulcanization degree is higher than the unvulcanized state but has notreached the degree needed for a final product.

(9-2-9) The tire of the ninth aspect of the invention may be configuredto include: a circular tire frame that is formed using a resin materialand has the outer circumferential surface which has been subjected tothe roughening treatment by allowing a particle-shaped blasting abrasiveto collide with the outer circumferential surface; and atire-constituting rubber member superposed on the outer circumferentialsurface which has been subjected to the roughening treatment, via thebonding agent.

When the circular tire frame which has been subjected to the rougheningtreatment is used as such, the bonding strength between the tire frameand the tire-constituting rubber member may be enhanced by the anchoreffect. In addition, since the outer circumferential surface has beensubjected to the roughening treatment, excellent wettability of thebonding agent is provided. Accordingly, the bonding agent is held in thestate of being uniformly applied onto the outer circumferential surfaceof the tire frame, the bonding strength between the tire frame and thetire-constituting rubber member is ensured, and thus peeling between thetire frame and the tire-constituting rubber member may be suppressed.

The tire of the tenth aspect of the invention may be configured asfollows as described in Embodiment 10-1.

(10-1-1) The tire of the tenth aspect of the invention may be configuredso that at least a part of the reinforcing cord member is embedded inthe outer circumference of the tire frame formed of a thermoplasticresin material in the tenth aspect of the invention in thecross-sectional view along the axial direction of the tire frame.

When a part of the reinforcing cord member is embedded in the outercircumference of the tire frame as such, a phenomenon in which airremains in the area around the cord during winding of the reinforcingcord member (incorporation of air) may further be suppressed. Whenincorporation of air into the area around the reinforcing cord member issuppressed, movement of the reinforcing cord member due to, for example,a force applied during running is suppressed. Accordingly, for example,in the case where the tire-constituting member is provided in the outercircumference of the tire frame to cover the entire reinforcing cordmember, since the movement of the reinforcing cord member is suppressed,an occurrence of peeling and the like between the members (including thetire frame) is suppressed, and durability is enhanced.

(10-1-2) The tire of the tenth aspect of the invention may be providedwith a tread formed of a material having higher wear resistance than thethermoplastic resin material, on the outer side in the radial directionof the reinforcing cord layer.

By having a configuration in which the tread that comes into contactwith the road surface is formed of the material having higher wearresistance than the thermoplastic resin material as such, the wearresistance of the tire may further be enhanced.

(10-1-3) In the tire of the tenth aspect of the invention, ⅕ or more ofthe diameter of the reinforcing cord member may be embedded in the outercircumference of the tire frame along the circumferential direction inthe cross-sectional view along the axial direction of the tire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord membermay be effectively suppressed, and thus movement of the reinforcing cordmember due to, for example, a force applied during running may furtherbe suppressed.

(10-1-4) The tire of the tenth aspect of the invention may be configuredso that the tire frame includes, on the inner side in the radialdirection, a bead portion that comes into contact with a bead seat and arim flange of a rim, and an annular bead core made of a metal materialis embedded in the bead portion.

By providing the bead portion which is a part for fitting onto the rimin the tire frame, and moreover, by embedding the annular bead core madeof the metal material in the bead portion as such, the tire frame (thatis, tire) may be firmly held on the rim, similarly to conventionalpneumatic tires made of rubber.

(10-1-5) The tire of the tenth aspect of the invention may be providedwith a sealing portion made of a material having higher sealingproperties (adhesion to the rim) than the thermoplastic resin material,in a part where the bead portion comes into contact with the rim.

By providing the sealing portion made of the material having highersealing properties than the thermoplastic resin material in the partwhere the tire frame and the rim come into contact with each other assuch, adhesion between the tire (the tire frame) and the rim may beenhanced. Accordingly, compared to a case where only the rim and thethermoplastic resin material are used, leakage of air in the tire mayfurther be suppressed. In addition, by providing the sealing portion,fittability onto the rim of the tire may be enhanced.

(10-1-6) The manufacturing method of the tire of the tenth aspect of theinvention may include: a tire frame piece forming step of forming a tireframe piece for constituting a part of the circular tire frame using athermoplastic resin material including at least a polyamide-basedthermoplastic elastomer and a polyester-based thermoplastic elastomer; atire frame piece bonding step of forming a tire frame by fusing two ormore tire frame pieces, which make a pair, by applying heat to thebonding surfaces of the tire frame pieces; and a reinforcing cord memberwinding step of winding a reinforcing cord member around the outercircumference of the tire frame in the circumferential direction to forma reinforcing cord layer.

(10-1-7) The manufacturing method of the tire may be configured so that,in the tire frame piece bonding step, the bonding surface of the tireframe piece is heated to a temperature equal to or higher than themelting point of the thermoplastic resin material that forms the tireframe piece.

When the bonding surface of the divided body is heated to a temperatureequal to or higher than the melting point of the thermoplastic resinmaterial that forms the tire frame piece as such, fusing between thetire frame pieces may be sufficiently performed. Therefore, productivityof the tire may be enhanced while enhancing durability of the tire.

(10-1-8) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, the reinforcing cord memberis wound around the outer circumference of the tire frame in a mannersuch that at least a part of the reinforcing cord member is embeddedwhile melting or softening the outer circumference of the tire frameformed in the tire frame piece bonding step.

By winding the reinforcing cord member around the outer circumference ofthe tire frame in a manner such that at least a part of the reinforcingcord member is embedded while melting and softening the outercircumference of the tire frame as such, the at least a part of thereinforcing cord member which is embedded and the melted or softenedthermoplastic resin material may be welded. Accordingly, incorporationof air between the outer circumference of the tire frame and thereinforcing cord member may further be suppressed in the cross-sectionalview along the axial direction of the tire frame. In addition, when thepart in which the reinforcing cord member is embedded is cooled andsolidified, the fixed condition of the reinforcing cord member embeddedin the tire frame is enhanced.

(10-1-9) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, ⅕ or more of the diameterof the reinforcing cord may be embedded in the outer circumference ofthe tire frame in the cross-sectional view along the axial direction ofthe tire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord duringmanufacturing may be effectively suppressed, and moreover, the embeddedreinforcing cord member may become less likely to be caused to come outof the tire frame.

(10-1-10) The manufacturing method of the tire may be configured sothat, in the reinforcing cord member winding step, the heatedreinforcing cord member is embedded in the tire frame.

When embedding the reinforcing cord member in the tire frame whileheating the reinforcing cord member in the reinforcing cord winding stepas such, when the heated reinforcing cord member comes into contact withthe outer circumference of the tire frame, the contact part is melted orsoftened. Therefore, it becomes easy to embed the reinforcing cordmember in the outer circumference of the tire frame.

(10-1-11) The manufacturing method of the tire may be configured sothat, in the cord member winding step, the part of the outercircumference of the tire frame for embedding the reinforcing cordmember is heated.

By heating the part of the outer circumference of the tire frame forembedding the reinforcing cord member as such, the heated part of thetire frame is melted or softened. Therefore, it becomes easy to embedthe reinforcing cord member.

(10-1-12) The manufacturing method of the tire may be configured sothat, in the cord member winding step, the reinforcing cord member iswound in a spiral shape in the circumferential direction of the outercircumference of the tire frame while pressing the reinforcing cordmember against the outer circumference of the tire frame.

When the reinforcing cord member is wound in the spiral shape whilepressing the reinforcing cord member against the outer circumference ofthe tire frame as such, the depth of embedding the reinforcing cordmember in the outer circumference of the tire frame may be adjusted.

(10-1-13) According to the manufacturing method, it may be configuredsuch that, in the cord member winding step, after winding thereinforcing cord member around the tire frame, the melted or softenedpart of the outer circumference of the tire frame is cooled.

By forcibly cooling the melted or softened part of the outercircumference of the tire frame after embedding the reinforcing cordmember as such, the melted or softened part of the outer circumferenceof the tire frame may be more quickly and rapidly cooled and solidifiedthan natural cooling. By cooling the outer circumference of the tiremore quickly than natural cooling, deformation of the outercircumference of the tire frame may be suppressed, and movement of thereinforcing cord member may be suppressed.

The tire of the tenth aspect of the invention may be configured asfollows as described in Embodiment 10-2.

(10-2-1) The tire of the tenth aspect of the invention may be configuredsuch that the manufacturing method further includes: a rougheningtreatment step of performing the roughening treatment on the outercircumferential surface of the tire frame by allowing a particle-shapedblasting abrasive to collide with the outer circumferential surface ofthe tire frame; and a superposing step of superposing atire-constituting rubber member on the outer circumferential surfacewhich has been subjected to the roughening treatment, via a bondingagent.

When the roughening treatment step is provided as such, theparticle-shaped blasting abrasive collides with the outercircumferential surface of the circular tire frame formed by using thethermoplastic resin material, and thus minute roughened unevenness isformed on the outer circumferential surface. The treatment of formingminute roughened unevenness by allowing the blasting abrasive to collidewith the outer circumferential surface of the tire frame is referred toas the roughening treatment. Thereafter, the tire-constituting rubbermember is superposed on the outer circumferential surface which has beensubjected to the roughening treatment, via the bonding agent. Here, whenthe tire frame and the tire-constituting rubber member are integratedinto each other, since the outer circumferential surface of the tireframe has been subjected to the roughening treatment, bonding properties(bonding properties) are enhanced due to the anchor effect. In addition,since the resin material that forms the tire frame is ploughed due tocollision of the blasting abrasive, wettability of the outercircumferential surface is enhanced. Accordingly, the outercircumferential surface of the tire frame is held in a state of beinguniformly coated with the bonding agent, and thus the bonding strengthbetween the tire frame and the tire-constituting rubber member may beensured.

(10-2-2) In the tire of the tenth aspect of the invention, at least apart of the outer circumferential surface of the tire frame may be anuneven portion, and the uneven portion may be subjected to theroughening treatment in the roughening treatment step.

Even if at least a part of the outer circumferential surface of the tireframe is the uneven portion as such, by allowing the blasting abrasiveto collide with the uneven portion, the area around a recess (walls atthe recess, the bottom of the recess) is subjected to the rougheningtreatment, and thus the bonding strength between the tire frame and thetire-constituting rubber member may be ensured.

(10-2-3) In the tire of the tenth aspect of the invention, the outercircumference of the tire frame is configured to have a reinforcinglayer that constitutes the uneven portion at the outer circumferentialsurface, and the reinforcing layer may be configured such that a coatedcord member formed by coating the reinforcing cord with a resin materialof the same kind as or different from the resin material that forms thetire frame is wound in the circumferential direction of the tire frame.

By configuring the outer circumference of the tire frame to have thereinforcing layer formed by winding the coated cord member in thecircumferential direction of the tire frame as such, the rigidity of thetire frame in the circumferential direction may be enhanced.

(10-2-4) The tire of the tenth aspect of the invention may use athermoplastic resin material as the resin material that is a componentof the coated cord member.

By using the thermoplastic material having thermoplasticity as the resinmaterial that is a component of the coated cord member as such, comparedto a case of using a thermosetting material as the resin material, thetire is easily manufactured and is easily recycled.

(10-2-5) The tire of the tenth aspect of the invention may be configuredso that, in the roughening treatment step, an area wider than the areafor superposing the tire-constituting rubber member is subjected to theroughening treatment.

When the area wider than the area for superposing the tire-constitutingrubber member is subjected to the roughening treatment in the rougheningtreatment step, the bonding strength between the tire frame and thetire-constituting rubber member may be reliably ensured.

(10-2-6) The tire of the tenth aspect of the invention may be configuredso that, in the roughening treatment step, the outer circumferentialsurface is subjected to the roughening treatment to have an arithmeticmean roughness Ra of 0.05 mm or greater.

When the outer circumferential surface of the tire frame is subjected tothe roughening treatment to have an arithmetic mean roughness Ra of 0.05mm or greater in the roughening treatment step as such, in a case wherethe tire-constituting rubber member, for example, in an unvulcanized orsemi-vulcanized state is superposed on the outer circumferential surfacewhich has been subjected to the roughening treatment, via the bondingagent, and is vulcanized, rubber of the tire-constituting rubber membermay be caused to flow to the bottom of the roughened uneven portionformed by the roughening treatment. When the rubber of thetire-constituting rubber member flows to the bottom of the rougheneduneven portion, a sufficient anchor effect is exhibited between theouter circumferential surface and the tire-constituting rubber member,and the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

(10-2-7) In the tire of the tenth aspect of the invention, a rubber inthe unvulcanized or semi-vulcanized state may be used as thetire-constituting rubber member.

In the case where the rubber in the unvulcanized or semi-vulcanizedstate is used as the tire-constituting rubber member as such, the rubberflows to the roughened uneven portion formed on the outercircumferential surface of the tire frame by the roughening treatmentwhen the tire-constituting rubber member is vulcanized. In addition,when vulcanization is completed, the anchor effect is exhibited by the(vulcanized) rubber that has flowed to the roughened uneven portion, andthus the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

“Vulcanized” is referred to as a state in which the degree ofvulcanization reaches the degree needed for a final product, and the“semi-vulcanized state” is referred to as a state in which thevulcanization degree is higher than the unvulcanized state but has notreached the degree needed for a final product.

(10-2-8) The tire of the tenth aspect of the invention may be configuredto include: a circular tire frame that is formed using the thermoplasticresin material in the tenth aspect of the invention and has the outercircumferential surface which has been subjected to the rougheningtreatment by allowing a particle-shaped blasting abrasive to collidewith the outer circumferential surface; and a tire-constituting rubbermember superposed on the outer circumferential surface which has beensubjected to the roughening treatment, via the bonding agent.

When the circular tire frame which has been subjected to the rougheningtreatment is used as such, the bonding strength between the tire frameand the tire-constituting rubber member may be enhanced by the anchoreffect. In addition, since the outer circumferential surface has beensubjected to the roughening treatment, excellent wettability of thebonding agent is provided. Accordingly, the bonding agent is held in thestate of being uniformly applied onto the outer circumferential surfaceof the tire frame, the bonding strength between the tire frame and thetire-constituting rubber member is ensured, and thus peeling between thetire frame and the tire-constituting rubber member may be suppressed.

The tire of the eleventh aspect of the invention may be configured asfollows as described in the Embodiment 11-1.

(11-1-1) The tire of the eleventh aspect of the invention may beconfigured so that at least a part of the reinforcing cord member isembedded in the outer circumference of the tire frame formed of athermoplastic resin material in the present invention in the eleventhaspect in the cross-sectional view along the axial direction of the tireframe.

When a part of the reinforcing cord member is embedded in the outercircumference of the tire frame as such, a phenomenon in which airremains in the area around the cord during winding of the reinforcingcord member (incorporation of air) may further be suppressed. Whenincorporation of air into the area around the reinforcing cord member issuppressed, movement of the reinforcing cord member due to, for example,a force applied during running is suppressed. Accordingly, for example,in the case where the tire-constituting member is provided on the outercircumference of the tire frame to cover the entire reinforcing cordmember, since the movement of the reinforcing cord member is suppressed,an occurrence of peeling and the like between the members (including thetire frame) is suppressed, and durability is enhanced.

(11-1-2) The tire of the eleventh aspect of the invention may beprovided with a tread formed of a material having higher wear resistancethan the thermoplastic resin material, on the outer side in the radialdirection of the reinforcing cord layer.

By having a configuration in which the tread that comes into contactwith the road surface is formed of the material having higher wearresistance than the thermoplastic resin material as such, the wearresistance of the tire may further be enhanced.

(11-1-3) In the tire of the eleventh aspect of the invention, ⅕ or moreof the diameter of the reinforcing cord member may be embedded in theouter circumference of the tire frame along the circumferentialdirection in the cross-sectional view along the axial direction of thetire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord membermay be effectively suppressed, and thus movement of the reinforcing cordmember due to, for example, a force applied during running may furtherbe suppressed.

(11-1-4) The tire of the eleventh aspect of the invention may beconfigured so that the tire frame includes, on the inner side in theradial direction, a bead portion that comes into contact with a beadseat and a rim flange of a rim, and an annular bead core made of a metalmaterial is embedded in the bead portion.

By providing the bead portion which is a part for fitting onto the rimin the tire frame, and moreover, by embedding the annular bead core madeof the metal material in the bead portion as such, the tire frame (thatis, tire) may be firmly held on the rim, similarly to conventionalpneumatic tires made of rubber.

(11-1-5) The tire of the eleventh aspect of the invention may beprovided with a sealing portion made of a material having higher sealingproperties (adhesion to the rim) than the thermoplastic resin material,in a part where the bead portion comes into contact with the rim.

By providing the sealing portion made of the material having highersealing properties than the thermoplastic resin material in the partwhere the tire frame and the rim come into contact with each other assuch, adhesion between the tire (the tire frame) and the rim may beenhanced. Accordingly, compared to a case where only the rim and thethermoplastic resin material are used, leakage of air in the tire mayfurther be suppressed. In addition, by providing the sealing portion,fittability onto the rim of the tire may be enhanced.

(11-1-6) The manufacturing method of the tire of the eleventh aspect ofthe invention may include: a tire frame piece forming step of forming atire frame piece for constituting a part of the circular tire frameusing a thermoplastic resin material including at least a mixed materialof a polyamide-based thermoplastic elastomer and a specific copolymer; atire frame piece bonding step of forming a tire frame by fusing two ormore tire frame pieces, which make a pair, by applying heat to thebonding surfaces of the tire frame pieces; and a reinforcing cord memberwinding step of winding a reinforcing cord member around the outercircumference of the tire frame in the circumferential direction to forma reinforcing cord layer.

As the thermoplastic resin material, specifically, for example, a mixedmaterial of a polyamide-based thermoplastic elastomer “UBESTA,XPA9055X1” manufactured by Ube Industries, Ltd. and a Zn ionomer of anethylene-methacrylic acid copolymer “HIMILAN, 1855Zn” manufactured by DuPont-Mitsui Polychemicals Co., Ltd. may be used.

(11-1-7) The manufacturing method of the tire may be configured so that,in the tire frame piece bonding step, the bonding surface of the tireframe piece is heated to a temperature equal to or higher than themelting point of the thermoplastic resin material that forms the tireframe piece.

When the bonding surface of the divided body is heated to a temperatureequal to or higher than the melting point of the thermoplastic resinmaterial that forms the tire frame piece as such, fusing between thetire frame pieces may be sufficiently performed. Therefore, productivityof the tire may be enhanced while enhancing durability of the tire.

(11-1-8) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, the reinforcing cord memberis wound around the outer circumference of the tire frame in a mannersuch that at least a part of the reinforcing cord member is embeddedwhile melting or softening the outer circumference of the tire frameformed in the tire frame piece bonding step.

By winding the reinforcing cord member around the outer circumference ofthe tire frame in a manner such that at least a part of the reinforcingcord member is embedded while melting and softening the outercircumference of the tire frame as such, the at least a part of thereinforcing cord member which is embedded and the melted or softenedthermoplastic resin material may be welded. Accordingly, incorporationof air between the outer circumference of the tire frame and thereinforcing cord member in the cross-sectional view along the axialdirection of the tire frame may further be suppressed. In addition, whenthe part in which the reinforcing cord member is embedded is cooled andsolidified, the fixed condition of the reinforcing cord member embeddedin the tire frame is enhanced.

(11-1-9) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, ⅕ or more of the diameterof the reinforcing cord may be embedded in the outer circumference ofthe tire frame in the cross-sectional view along the axial direction ofthe tire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord duringmanufacturing may be effectively suppressed, and moreover, the embeddedreinforcing cord member may become less likely to be caused to come outof the tire frame.

(11-1-10) The manufacturing method of the tire may be configured sothat, in the reinforcing cord member winding step, the heatedreinforcing cord member is embedded in the tire frame.

By embedding the reinforcing cord member while heating the reinforcingcord member in the reinforcing cord winding step as such, when theheated reinforcing cord member comes into contact with the outercircumference of the tire frame, the contact part is melted or softened.Therefore, it becomes easy to embed the reinforcing cord member in theouter circumference of the tire frame.

(11-1-11) The manufacturing method of the tire may be configured sothat, in the cord member winding step, the part of the outercircumference of the tire frame for embedding the reinforcing cordmember is heated.

By heating the part of the outer circumference of the tire frame forembedding the reinforcing cord member as such, the heated part of thetire frame is melted or softened. Therefore, it becomes easy to embedthe reinforcing cord member.

(11-1-12) The manufacturing method of the tire may be configured sothat, in the cord member winding step, the reinforcing cord member iswound in a spiral shape in the circumferential direction of the outercircumference of the tire frame while pressing the reinforcing cordmember against the outer circumference of the tire frame.

When the reinforcing cord member is wound in the spiral shape whilepressing the reinforcing cord member against the outer circumference ofthe tire frame as such, the depth of embedding the reinforcing cordmember in the outer circumference of the tire frame may be adjusted.

(11-1-13) According to the manufacturing method, it may be configuredsuch that, in the cord member winding step, after winding thereinforcing cord member around the tire frame, the melted or softenedpart of the outer circumference of the tire frame is cooled.

By forcibly cooling the melted or softened part of the outercircumference of the tire frame after embedding the reinforcing cordmember as such, the melted or softened part of the outer circumferenceof the tire frame may be more quickly and rapidly cooled and solidifiedthan natural cooling. By cooling the outer circumference of the tiremore quickly than natural cooling, deformation of the outercircumference of the tire frame may be suppressed, and movement of thereinforcing cord member may be suppressed.

The tire of the eleventh aspect of the invention may be configured asfollows as described in Embodiment 11-2.

(11-2-1) The tire of the eleventh aspect of the invention may beconfigured such that the manufacturing method further includes: aroughening treatment step of performing the roughening treatment on theouter circumferential surface of the tire frame by allowing aparticle-shaped blasting abrasive to collide with the outercircumferential surface of the tire frame; and a superposing step ofsuperposing a tire-constituting rubber member on the outercircumferential surface which has been subjected to the rougheningtreatment, via a bonding agent.

When the roughening treatment step is provided as such, theparticle-shaped blasting abrasive collides with the outercircumferential surface of the circular tire frame formed using thethermoplastic resin material, and thus minute roughened unevenness isformed on the outer circumferential surface. The treatment of formingminute roughened unevenness by allowing the blasting abrasive to collidewith the outer circumferential surface of the tire frame is referred toas the roughening treatment. Thereafter, the tire-constituting rubbermember is superposed on the outer circumferential surface which has beensubjected to the roughening treatment, via the bonding agent. Here, whenthe tire frame and the tire-constituting rubber member are integratedinto each other, since the outer circumferential surface of the tireframe has been subjected to the roughening treatment, bonding properties(bonding properties) are enhanced due to the anchor effect. In addition,since the resin material that forms the tire frame is ploughed due tocollision of the blasting abrasive, wettability of the outercircumferential surface is enhanced. Accordingly, the outercircumferential surface of the tire frame is held in a state of beinguniformly coated with the bonding agent, and thus the bonding strengthbetween the tire frame and the tire-constituting rubber member may beensured.

(11-2-2) In the tire of the eleventh aspect of the invention, at least apart of the outer circumferential surface of the tire frame may be anuneven portion, and the uneven portion may be subjected to theroughening treatment in the roughening treatment step.

Even if at least a part of the outer circumferential surface of the tireframe is the uneven portion as such, by allowing the blasting abrasiveto collide with the uneven portion, the area around a recess (walls atthe recess, the bottom of the recess) is subjected to the rougheningtreatment, and thus the bonding strength between the tire frame and thetire-constituting rubber member may be ensured.

(11-2-3) In the tire of the eleventh aspect of the invention, the outercircumference of the tire frame is configured to have a reinforcinglayer that constitutes the uneven portion at the outer circumferentialsurface, and the reinforcing layer may be configured such that a coatedcord member formed by coating the reinforcing cord with a resin materialof the same kind as or different from the resin material that forms thetire frame is wound in the circumferential direction of the tire frame.

By configuring the outer circumference of the tire frame to have thereinforcing layer formed by winding the coated cord member in thecircumferential direction of the tire frame as such, the rigidity of thetire frame in the circumferential direction may be enhanced.

(11-2-4) In the tire of the eleventh aspect of the invention, athermoplastic resin material may be used as the resin material that is acomponent of the coated cord member.

By using the thermoplastic material having thermoplasticity as the resinmaterial that is a component of the coated cord member as such, comparedto a case of using a thermosetting material as the resin material, thetire is easily manufactured and is easily recycled.

(11-2-5) The tire of the eleventh aspect of the invention may beconfigured so that, in the roughening treatment step, an area wider thanthe area for superposing the tire-constituting rubber member issubjected to the roughening treatment.

When the area wider than the area for superposing the tire-constitutingrubber member is subjected to the roughening treatment in the rougheningtreatment step, the bonding strength between the tire frame and thetire-constituting rubber member may be reliably ensured.

(11-2-6) The tire of the eleventh aspect of the invention may beconfigured so that, in the roughening treatment step, the outercircumferential surface is subjected to the roughening treatment to havean arithmetic mean roughness Ra of 0.05 mm or greater.

When the outer circumferential surface of the tire frame is subjected tothe roughening treatment to have an arithmetic mean roughness Ra of 0.05mm or greater in the roughening treatment step as such, in a case wherethe tire-constituting rubber member, for example, in an unvulcanized orsemi-vulcanized state is superposed on the outer circumferential surfacewhich has been subjected to the roughening treatment, via the bondingagent, and is vulcanized, rubber of the tire-constituting rubber membermay be caused to flow to the bottom of the roughened uneven portionformed by the roughening treatment. When the rubber of thetire-constituting rubber member flows to the bottom of the rougheneduneven portion, a sufficient anchor effect is exhibited between theouter circumferential surface and the tire-constituting rubber member,and the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

(11-2-7) In the tire of the eleventh aspect of the invention, a rubberin the unvulcanized or semi-vulcanized state may be as thetire-constituting rubber member.

In the case where the rubber in the unvulcanized or semi-vulcanizedstate is used as the tire-constituting rubber member as such, the rubberflows to the roughened uneven portion formed on the outercircumferential surface of the tire frame by the roughening treatmentwhen the tire-constituting rubber member is vulcanized. In addition,when vulcanization is completed, the anchor effect is exhibited by the(vulcanized) rubber that has flowed to the roughened uneven portion, andthus the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

“Vulcanized” is referred to as a state in which the degree ofvulcanization reaches the degree needed for a final product, and the“semi-vulcanized state” is referred to as a state in which thevulcanization degree is higher than the unvulcanized state but has notreached the degree needed for a final product.

(11-2-8) The tire of the eleventh aspect of the invention may beconfigured to include: a circular tire frame that is formed by using thethermoplastic resin material in the eleventh aspect the invention andhas the outer circumferential surface which has been subjected to theroughening treatment by allowing a particle-shaped blasting abrasive tocollide with on the outer circumferential surface; and thetire-constituting rubber member superposed on the outer circumferentialsurface which has been subjected to the roughening treatment via thebonding agent.

When the circular tire frame which has been subjected to the rougheningtreatment is used as such, the bonding strength between the tire frameand the tire-constituting rubber member may be enhanced by the anchoreffect. In addition, since the outer circumferential surface has beensubjected to the roughening treatment, excellent wettability of thebonding agent is provided. Accordingly, the bonding agent is held in thestate of being uniformly applied onto the outer circumferential surfaceof the tire frame, the bonding strength between the tire frame and thetire-constituting rubber member is ensured, and thus peeling between thetire frame and the tire-constituting rubber member may be suppressed.

The tire of the twelfth aspect of the invention may be configured asfollows as described in Embodiment 12-1.

(12-1-1) The tire of the twelfth aspect of the invention may beconfigured so that at least a part of the reinforcing cord member isembedded in the outer circumference of the tire frame formed of athermoplastic resin material in the twelfth aspect of the invention inthe cross-sectional view along the axial direction of the tire frame.

When a part of the reinforcing cord member is embedded in the outercircumference of the tire frame as such, a phenomenon in which airremains in the area around the cord during winding of the reinforcingcord member (incorporation of air) may further be suppressed. Whenincorporation of air into the area around the reinforcing cord member issuppressed, movement of the reinforcing cord member due to, for example,a force applied during running is suppressed. Accordingly, for example,in the case where the tire-constituting member is provided in the outercircumference of the tire frame to cover the entire reinforcing cordmember, since the movement of the reinforcing cord member is suppressed,an occurrence of peeling and the like between the members (including thetire frame) is suppressed, and durability is enhanced.

(12-1-2) The tire of the twelfth aspect of the invention may be providedwith a tread formed of a material having higher wear resistance than thethermoplastic resin material, on the outer side in the radial directionof the reinforcing cord layer.

By having a configuration in which the tread that comes into contactwith the road surface is formed of the material having higher wearresistance than the thermoplastic resin material as such, the wearresistance of the tire may further be enhanced.

(12-1-3) In the tire of the twelfth aspect of the invention, ⅕ or moreof the diameter of the reinforcing cord member may be embedded in theouter circumference of the tire frame along the circumferentialdirection in the cross-sectional view along the axial direction of thetire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord membermay be effectively suppressed, and thus movement of the reinforcing cordmember due to, for example, a force applied during running may furtherbe suppressed.

(12-1-4) The tire of the twelfth aspect of the invention may beconfigured so that the tire frame includes, on the inner side in theradial direction, a bead portion that comes into contact with a beadseat and a rim flange of a rim, and an annular bead core made of a metalmaterial is embedded in the bead portion.

By providing the bead portion which is a part for fitting onto the rimin the tire frame, and moreover, by embedding the annular bead core madeof the metal material in the bead portion as such, the tire frame (thatis, tire) may be firmly held on the rim, similarly to conventionalpneumatic tires made of rubber.

(12-1-5) The tire of the twelfth aspect of the invention may be providedwith a sealing portion made of a material having higher sealingproperties (adhesion to the rim) than the thermoplastic resin material,in a part where the bead portion comes into contact with the rim.

By providing the sealing portion made of the material having highersealing properties than the thermoplastic resin material in the partwhere the tire frame and the rim come into contact with each other assuch, adhesion between the tire (the tire frame) and the rim may beenhanced. Accordingly, compared to a case where only the rim and thethermoplastic resin material are used, leakage of air in the tire mayfurther be suppressed. In addition, by providing the sealing portion,fittability onto the rim of the tire may be enhanced.

(12-1-6) The manufacturing method of the tire of the twelfth aspect ofthe invention may include: a tire frame piece forming step of forming atire frame piece for constituting a part of the circular tire frameusing a thermoplastic resin material including at least apolyamide-based thermoplastic elastomer (for example, “UBESTA,XPA9055X1” manufactured by Ube Industries, Ltd.), a specific copolymer(for example, an ethylene-methacrylic acid copolymer “NUCREL N035C”manufactured by Du Pont-Mitsui Polychemicals Co., Ltd.), and a specificacid-modified copolymer (for example, an acid-modified product of anethylene-acrylate ethyl ester copolymer “HPR, AR2011” manufactured by DuPont-Mitsui Polychemicals Co., Ltd.); a tire frame piece bonding step offorming a tire frame by fusing two or more tire frame pieces, which makea pair, by applying heat to the bonding surfaces of the tire framepieces; and a reinforcing cord member winding step of winding areinforcing cord member around the outer circumference of the tire framein the circumferential direction to form a reinforcing cord layer.

As described above, the thermoplastic resin material including apolyamide-based thermoplastic elastomer, a specific copolymer, and aspecific acid-modified copolymer has excellent liquidity, and thusinjection molding may be easily performed. Therefore, when a tire framepiece for constituting a part of the circular tire frame is formed usingthe thermoplastic resin material in the twelfth aspect of the invention,in the case where the tire frame piece is formed by injection molding,the tire frame piece may be effectively formed, resulting in excellentproductivity of the tire.

(12-1-7) The manufacturing method of the tire may be configured so that,in the tire frame piece bonding step, the bonding surface of the tireframe piece is heated to a temperature equal to or higher than themelting point of the thermoplastic resin material that forms the tireframe piece.

When the bonding surface of the divided body is heated to a temperatureequal to or higher than the melting point of the thermoplastic resinmaterial that forms the tire frame piece as such, fusing between thetire frame pieces may be sufficiently performed. Therefore, productivityof the tire may be enhanced while enhancing durability of the tire.

(12-1-8) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, the reinforcing cord memberis wound around the outer circumference of the tire frame in a mannersuch that at least a part of the reinforcing cord member is embeddedwhile melting or softening the outer circumference of the tire frameformed in the tire frame piece bonding step.

By winding the reinforcing cord member around the outer circumference ofthe tire frame in a manner such that at least a part of the reinforcingcord member is embedded while melting and softening the outercircumference of the tire frame as such, the at least a part of thereinforcing cord member which is embedded and the melted or softenedthermoplastic resin material may be welded. Accordingly, incorporationof air between the outer circumference of the tire frame and thereinforcing cord member in the cross-sectional view along the axialdirection of the tire frame may further be suppressed. In addition, whenthe part in which the reinforcing cord member is embedded is cooled andsolidified, the fixed condition of the reinforcing cord member embeddedin the tire frame is enhanced.

(12-1-9) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, ⅕ or more of the diameterof the reinforcing cord may be embedded in the outer circumference ofthe tire frame in the cross-sectional view along the axial direction ofthe tire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord duringmanufacturing may be effectively suppressed, and moreover, the embeddedreinforcing cord member may become less likely to be caused to come outof the tire frame.

(12-1-10) The manufacturing method of the tire may be configured sothat, in the reinforcing cord member winding step, the heatedreinforcing cord member is embedded in the tire frame.

By embedding the reinforcing cord member in the tire frame while heatingthe reinforcing cord member in the reinforcing cord winding step assuch, when the heated reinforcing cord member comes into contact withthe outer circumference of the tire frame, the contact part is melted orsoftened. Therefore, it becomes easy to embed the reinforcing cordmember in the outer circumference of the tire frame.

(12-1-11) The manufacturing method of the tire may be configured sothat, in the cord member winding step, the part of the outercircumference of the tire frame for embedding the reinforcing cordmember is heated.

By heating the part of the outer circumference of the tire frame forembedding the reinforcing cord member as such, the heated part of thetire frame is melted or softened. Therefore, it becomes easy to embedthe reinforcing cord member.

(12-1-12) The manufacturing method of the tire may be configured sothat, in the cord member winding step, the reinforcing cord member iswound in a spiral shape in the circumferential direction of the outercircumference of the tire frame while pressing the reinforcing cordmember against the outer circumference of the tire frame.

When the reinforcing cord member is wound in the spiral shape whilepressing the reinforcing cord member against the outer circumference ofthe tire frame as such, the depth of embedding the reinforcing cordmember in the outer circumference of the tire frame may be adjusted.

(12-1-13) According to the manufacturing method, the configuration inwhich, in the cord member winding step, after winding the reinforcingcord member around the tire frame, the melted or softened part of theouter circumference of the tire frame is cooled.

By forcibly cooling the melted or softened part of the outercircumference of the tire frame after embedding the reinforcing cordmember as such, the melted or softened part of the outer circumferenceof the tire frame may be more quickly and rapidly cooled and solidifiedthan natural cooling. By cooling the outer circumference of the tiremore quickly than natural cooling, deformation of the outercircumference of the tire frame may be suppressed, and movement of thereinforcing cord member may be suppressed.

The tire of the twelfth aspect of the invention may be configured asfollows as described in Embodiment 12-2.

(12-2-1) The tire of the twelfth aspect of the invention may beconfigured such that the manufacturing method further includes: aroughening treatment step of performing the roughening treatment on theouter circumferential surface of the tire frame by allowing aparticle-shaped blasting abrasive to collide with the outercircumferential surface of the tire frame; and a superposing step ofsuperposing a tire-constituting rubber member on the outercircumferential surface which has been subjected to the rougheningtreatment, via a bonding agent.

When the roughening treatment step is provided as such, theparticle-shaped blasting abrasive collides with the outercircumferential surface of the circular tire frame formed by using thethermoplastic resin material, and thus minute roughened unevenness isformed on the outer circumferential surface. The treatment of formingminute roughened unevenness by allowing the blasting abrasive to collidewith the outer circumferential surface of the tire frame is referred toas the roughening treatment. Thereafter, the tire-constituting rubbermember is superposed on the outer circumferential surface which has beensubjected to the roughening treatment, via the bonding agent. Here, whenthe tire frame and the tire-constituting rubber member are integratedinto each other, since the outer circumferential surface of the tireframe is subjected to the roughening treatment, bonding properties(adhesiveness) are enhanced due to the anchor effect. In addition, sincethe resin material that forms the tire frame is ploughed due tocollision of the blasting abrasive, wettability of the outercircumferential surface is enhanced. Accordingly, the outercircumferential surface of the tire frame is held in a state of beinguniformly coated with the bonding agent, and thus the bonding strengthbetween the tire frame and the tire-constituting rubber member may beensured.

(12-2-2) In the tire of the twelfth aspect of the invention, at least apart of the outer circumferential surface of the tire frame may be anuneven portion, and the uneven portion may be subjected to theroughening treatment in the roughening treatment step.

Even if at least a part of the outer circumferential surface of the tireframe is the uneven portion as such, by allowing the blasting abrasiveto collide with the uneven portion, the area around a recess (walls atthe recess, the bottom of the recess) is subjected to the rougheningtreatment, and thus the bonding strength between the tire frame and thetire-constituting rubber member may be ensured.

(12-2-3) In the tire of the twelfth aspect of the invention, the outercircumference of the tire frame is configured to have a reinforcinglayer that constitutes the uneven portion at the outer circumferentialsurface, and the reinforcing layer may be configured such that a coatedcord member formed by coating the reinforcing cord with a resin materialof the same kind as or different from the resin material that forms thetire frame is wound in the circumferential direction of the tire frame.

By configuring the outer circumference of the tire frame to have thereinforcing layer formed by winding the coated cord member in thecircumferential direction of the tire frame as such, the rigidity of thetire frame in the circumferential direction may be enhanced.

(12-2-4) In the tire of the twelfth aspect of the invention, athermoplastic resin material may be used as the resin material that is acomponent of the coated cord member.

By using the thermoplastic material having thermoplasticity as the resinmaterial that is a component of the coated cord member as such, comparedto a case of using a thermosetting material as the resin material, thetire is easily manufactured and is easily recycled.

(12-2-5) The tire of the twelfth aspect of the invention may beconfigured so that, in the roughening treatment step, an area wider thanthe area for superposing the tire-constituting rubber member issubjected to the roughening treatment.

When the area wider than the area for superposing the tire-constitutingrubber member is subjected to the roughening treatment in the rougheningtreatment step, the bonding strength between the tire frame and thetire-constituting rubber member may be reliably ensured.

(12-2-6) The tire of the twelfth aspect of the invention may beconfigured so that, in the roughening treatment step, the outercircumferential surface is subjected to the roughening treatment to havean arithmetic mean roughness Ra of 0.05 mm or greater.

When the outer circumferential surface of the tire frame is subjected tothe roughening treatment to have an arithmetic mean roughness Ra of 0.05mm or greater in the roughening treatment step as such, in a case wherethe tire-constituting rubber member, for example, in an unvulcanized orsemi-vulcanized state is superposed on the outer circumferential surfacewhich has been subjected to the roughening treatment, via the bondingagent, and is vulcanized, rubber of the tire-constituting rubber membermay be caused to flow to the bottom of the roughened uneven portionformed by the roughening treatment. When the rubber of thetire-constituting rubber member flows to the bottom of the rougheneduneven portion, a sufficient anchor effect is exhibited between theouter circumferential surface and the tire-constituting rubber member,and the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

(12-2-7) In the tire of the twelfth aspect of the invention, a rubber inthe unvulcanized or semi-vulcanized state may be used as thetire-constituting rubber member.

In the case where the rubber in the unvulcanized or semi-vulcanizedstate is used as the tire-constituting rubber member as such, the rubberflows to the roughened uneven portion formed on the outercircumferential surface of the tire frame by the roughening treatmentwhen the tire-constituting rubber member is vulcanized. In addition,when vulcanization is completed, the anchor effect is exhibited by the(vulcanized) rubber that has flowed to the roughened uneven portion, andthus the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

“Vulcanized” is referred to as a state in which the degree ofvulcanization reaches the degree needed for a final product, and the“semi-vulcanized state” is referred to as a state in which thevulcanization degree is higher than the unvulcanized state but has notreached the degree needed for a final product.

(12-2-8) The tire of the twelfth aspect of the invention may beconfigured to include: a circular tire frame that is formed by using thethermoplastic resin material in the twelfth aspect of the invention andhas the outer circumferential surface which has been subjected to theroughening treatment by allowing a particle-shaped blasting abrasive tocollide with the outer circumferential surface; and a tire-constitutingrubber member superposed on the outer circumferential surface which hasbeen subjected to the roughening treatment, via a bonding agent.

When the circular tire frame which has been subjected to the rougheningtreatment is used as such, the bonding strength between the tire frameand the tire-constituting rubber member may be enhanced by the anchoreffect. In addition, since the outer circumferential surface has beensubjected to the roughening treatment, excellent wettability of thebonding agent is provided. Accordingly, the bonding agent is held in thestate of being uniformly applied onto the outer circumferential surfaceof the tire frame, the bonding strength between the tire frame and thetire-constituting rubber member is ensured, and thus peeling between thetire frame and the tire-constituting rubber member may be suppressed.

The tire of the thirteenth aspect of the invention may be configured asfollows as described in Embodiment 13-1.

(13-1-1) The tire of the thirteenth aspect of the invention may beconfigured so that at least a part of the reinforcing cord member isembedded in the outer circumference of the tire frame formed of athermoplastic resin material in the thirteenth aspect of the inventionin the cross-sectional view along the axial direction of the tire frame.

When a part of the reinforcing cord member is embedded in the outercircumference of the tire frame as such, a phenomenon in which airremains in the area around the cord during winding of the reinforcingcord member (incorporation of air) may further be suppressed. Whenincorporation of air into the area around the reinforcing cord member issuppressed, movement of the reinforcing cord member due to, for example,a force applied during running is suppressed. Accordingly, for example,in the case where the tire-constituting member is provided in the outercircumference of the tire frame to cover the entire reinforcing cordmember, since the movement of the reinforcing cord member is suppressed,an occurrence of peeling and the like between the members (including thetire frame) is suppressed, and durability is enhanced.

(13-1-2) The tire of the thirteenth aspect of the invention may beprovided with a tread formed of a material having higher wear resistancethan the thermoplastic resin material, on the outer side in the radialdirection of the reinforcing cord layer.

By having a configuration in which the tread that comes into contactwith the road surface is formed of the material having higher wearresistance than the thermoplastic resin material as such, the wearresistance of the tire may further be enhanced.

(13-1-3) In the tire of the thirteenth aspect of the invention, ⅕ ormore of the diameter of the reinforcing cord member may be embedded inthe outer circumference of the tire frame along the circumferentialdirection in the cross-sectional view along the axial direction of thetire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord membermay be effectively suppressed, and thus movement of the reinforcing cordmember due to, for example, a force applied during running may furtherbe suppressed.

(13-1-4) The tire of the thirteenth aspect of the invention may beconfigured so that the tire frame includes, on the inner side in theradial direction, a bead portion that comes into contact with a beadseat and a rim flange of a rim, and an annular bead core made of a metalmaterial is embedded in the bead portion.

By providing the bead portion which is a part for fitting onto the rimin the tire frame, and moreover, by embedding the annular bead core madeof the metal material in the bead portion as such, the tire frame (thatis, tire) may be firmly held on the rim, similarly to conventionalpneumatic tires made of rubber.

(13-1-5) The tire of the thirteenth aspect of the invention may beprovided with a sealing portion made of a material having higher sealingproperties (adhesion to the rim) than the thermoplastic resin material,in a part where the bead portion comes into contact with the rim.

By providing the sealing portion made of the material having highersealing properties than the thermoplastic resin material in the partwhere the tire frame and the rim come into contact with each other assuch, adhesion between the tire (the tire frame) and the rim may beenhanced. Accordingly, compared to a case where only the rim and thethermoplastic resin material are used, leakage of air in the tire mayfurther be suppressed. In addition, by providing the sealing portion,fittability onto the rim of the tire may be enhanced.

(13-1-6) The manufacturing method of the tire of the thirteenth aspectof the invention may include: a tire frame piece forming step of forminga tire frame piece for constituting a part of the circular tire frameusing a thermoplastic resin material including at least apolyamide-based thermoplastic elastomer and a rubber; a tire frame piecebonding step of forming a tire frame by fusing two or more tire framepieces, which make a pair, by applying heat to the bonding surfaces ofthe tire frame pieces; and a reinforcing cord member winding step ofwinding a reinforcing cord member around the outer circumference of thetire frame in the circumferential direction to form a reinforcing cordlayer.

(13-1-7) The manufacturing method of the tire may be configured so that,in the tire frame piece bonding step, the bonding surface of the tireframe piece is heated to a temperature equal to or higher than themelting point of the thermoplastic resin material that forms the tireframe piece.

When the bonding surface of the divided body is heated to a temperatureequal to or higher than the melting point of the thermoplastic resinmaterial that forms the tire frame piece as such, fusing between thetire frame pieces may be sufficiently performed. Therefore, productivityof the tire may be enhanced while enhancing durability of the tire.

(13-1-8) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, the reinforcing cord memberis wound around the outer circumference of the tire frame in a mannersuch that at least a part of the reinforcing cord member is embeddedwhile melting or softening the outer circumference of the tire frameformed in the tire frame piece bonding step.

By winding the reinforcing cord member around the outer circumference ofthe tire frame in a manner such that at least a part of the reinforcingcord member is embedded while melting and softening the outercircumference of the tire frame as such, the at least a part of thereinforcing cord member which is embedded and the melted or softenedthermoplastic resin material may be welded. Accordingly, incorporationof air between the outer circumference of the tire frame and thereinforcing cord member in the cross-sectional view along the axialdirection of the tire frame may further be suppressed. In addition, whenthe part in which the reinforcing cord member is embedded is cooled andsolidified, the fixed condition of the reinforcing cord member embeddedin the tire frame is enhanced.

(13-1-9) The manufacturing method of the tire may be configured so that,in the reinforcing cord member winding step, ⅕ or more of the diameterof the reinforcing cord may be embedded in the outer circumference ofthe tire frame in the cross-sectional view along the axial direction ofthe tire frame.

When ⅕ or more of the diameter of the reinforcing cord member isembedded in the outer circumference of the tire frame in thecross-sectional view along the axial direction of the tire frame,incorporation of air into the area around the reinforcing cord duringmanufacturing may be effectively suppressed, and moreover, the embeddedreinforcing cord member may become less likely to be caused to come outof the tire frame.

(13-1-10) The manufacturing method of the tire may be configured sothat, in the reinforcing cord member winding step, the heatedreinforcing cord member is embedded in the tire frame.

By embedding the reinforcing cord member in the tire frame whilehetingthe reinforcing cord member in the reinforcing cord winding step assuch, when the heated reinforcing cord member comes into contact withthe outer circumference of the tire frame, the contact part is melted orsoftened. Therefore, it becomes easy to embed the reinforcing cordmember in the outer circumference of the tire frame.

(13-1-11) The manufacturing method of the tire may be configured sothat, in the cord member winding step, the part of the outercircumference of the tire frame for embedding the reinforcing cordmember is heated.

By heating the part of the outer circumference of the tire frame forembedding the reinforcing cord member as such, the heated part of thetire frame is melted or softened. Therefore, it becomes easy to embedthe reinforcing cord member.

(13-1-12) The manufacturing method of the tire may be configured sothat, in the cord member winding step, the reinforcing cord member iswound in a spiral shape in the circumferential direction of the outercircumference of the tire frame while pressing the reinforcing cordmember against the outer circumference of the tire frame.

When the reinforcing cord member is wound in the spiral shape whilepressing the reinforcing cord member against the outer circumference ofthe tire frame as such, the depth of embedding the reinforcing cordmember in the outer circumference of the tire frame may be adjusted.

(13-1-13) According to the manufacturing method, it may be configuredsuch that, in the cord member winding step, after winding thereinforcing cord member around the tire frame, the melted or softenedpart of the outer circumference of the tire frame is cooled.

By forcibly cooling the melted or softened part of the outercircumference of the tire frame after embedding the reinforcing cordmember as such, the melted or softened part of the outer circumferenceof the tire frame may be more quickly and rapidly cooled and solidifiedthan natural cooling. By cooling the outer circumference of the tiremore quickly than natural cooling, deformation of the outercircumference of the tire frame may be suppressed, and movement of thereinforcing cord member may be suppressed.

The tire of the thirteenth aspect of the invention may be configured asfollows as described in Embodiment 13-2.

(13-2-1) The tire of the thirteenth aspect of the invention may beconfigured such that the manufacturing method further includes: aroughening treatment step of performing the roughening treatment on theouter circumferential surface of the tire frame by allowing aparticle-shaped blasting abrasive to collide with the outercircumferential surface of the tire frame; and a superposing step ofsuperposing a tire-constituting rubber member on the outercircumferential surface which has been subjected to the rougheningtreatment, via a bonding agent.

When the roughening treatment step is provided as such, theparticle-shaped blasting abrasive collides with the outercircumferential surface of the circular tire frame formed by using thethermoplastic resin material, and thus minute roughened unevenness isformed on the outer circumferential surface. The treatment of formingminute roughened unevenness by allowing the blasting abrasive to collidewith the outer circumferential surface of the tire frame is referred toas the roughening treatment. Thereafter, the tire-constituting rubbermember is superposed on the outer circumferential surface which has beensubjected to the roughening treatment, via the bonding agent. Here, whenthe tire frame and the tire-constituting rubber member are integratedinto each other, since the outer circumferential surface of the tireframe has been subjected to the roughening treatment, bonding properties(bonding properties) are enhanced due to the anchor effect. In addition,since the resin material that forms the tire frame is ploughed due tocollision of the blasting abrasive, wettability of the outercircumferential surface is enhanced. Accordingly, the outercircumferential surface of the tire frame is held in a state of beinguniformly coated with the bonding agent, and thus the bonding strengthbetween the tire frame and the tire-constituting rubber member may beensured.

(13-2-2) In the tire of the thirteenth aspect of the invention, at leasta part of the outer circumferential surface of the tire frame may be anuneven portion, and the uneven portion may be subjected to theroughening treatment in the roughening treatment step.

Even if at least a part of the outer circumferential surface of the tireframe is the uneven portion as such, by allowing the blasting abrasiveto collide with the uneven portion, the area around a recess (walls atthe recess, the bottom of the recess) is subjected to the rougheningtreatment, and thus the bonding strength between the tire frame and thetire-constituting rubber member may be ensured.

(13-2-3) In the tire of the thirteenth aspect of the invention, theouter circumference of the tire frame is configured to have areinforcing layer that constitutes the uneven portion at the outercircumferential surface, and the reinforcing layer may be configuredsuch that a coated cord member formed by coating the reinforcing cordwith a resin material of the same kind as or different from the resinmaterial that forms the tire frame is wound in the circumferentialdirection of the tire frame.

By configuring the outer circumference of the tire frame to have thereinforcing layer formed by winding the coated cord member in thecircumferential direction of the tire frame as such, the rigidity of thetire frame in the circumferential direction may be enhanced.

(13-2-4) In the tire of the thirteenth aspect of the invention, athermoplastic resin material may be used as the resin material that is acomponent of the coated cord member.

By using the thermoplastic material having thermoplasticity as the resinmaterial that is a component of the coated cord member as such, comparedto a case of using a thermosetting material as the resin material, thetire is easily manufactured and is easily recycled.

(13-2-5) The tire of the thirteenth aspect of the invention may beconfigured so that, in the roughening treatment step, an area wider thanthe area for superposing the tire-constituting rubber member issubjected to the roughening treatment.

When the area wider than the area for superposing the tire-constitutingrubber member is subjected to the roughening treatment in the rougheningtreatment step, the bonding strength between the tire frame and thetire-constituting rubber member may be reliably ensured.

(13-2-6) The tire of the thirteenth aspect of the invention may beconfigured so that, in the roughening treatment step, the outercircumferential surface is subjected to the roughening treatment to havean arithmetic mean roughness Ra of 0.05 mm or greater.

When the outer circumferential surface of the tire frame is subjected tothe roughening treatment to have an arithmetic mean roughness Ra of 0.05mm or greater in the roughening treatment step as such, in a case wherethe tire-constituting rubber member, for example, in an unvulcanized orsemi-vulcanized state is superposed on the outer circumferential surfacewhich has been subjected to the roughening treatment, via the bondingagent, and is vulcanized, rubber of the tire-constituting rubber membermay be caused to flow to the bottom of the roughened uneven portionformed by the roughening treatment. When the rubber of thetire-constituting rubber member flows to the bottom of the rougheneduneven portion, a sufficient anchor effect is exhibited between theouter circumferential surface and the tire-constituting rubber member,and the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

(13-2-7) In the tire of the thirteenth aspect of the invention, a rubberin the unvulcanized or semi-vulcanized state may be used as thetire-constituting rubber member.

In the case where the rubber in the unvulcanized or semi-vulcanizedstate is used as the tire-constituting rubber member as such, the rubberflows to the roughened uneven portion formed on the outercircumferential surface of the tire frame by the roughening treatmentwhen the tire-constituting rubber member is vulcanized. In addition,when vulcanization is completed, the anchor effect is exhibited by the(vulcanized) rubber that has flowed to the roughened uneven portion, andthus the bonding strength between the tire frame and thetire-constituting rubber member may be enhanced.

“Vulcanized” is referred to as a state in which the degree ofvulcanization reaches the degree needed for a final product, and the“semi-vulcanized state” is referred to as a state in which thevulcanization degree is higher than the unvulcanized state but has notreached the degree needed for a final product.

(13-2-8) The tire of the thirteenth aspect of the invention may beconfigured to include: a circular tire frame that is formed using thethermoplastic resin material in the thirteenth aspect of the inventionand has the outer circumferential surface which has been subjected tothe roughening treatment by allowing a particle-shaped blasting abrasiveto collide with the outer circumferential surface; and atire-constituting rubber member superposed on the outer circumferentialsurface which has been subjected to the roughening treatment, via abonding agent.

When the circular tire frame which has been subjected to the rougheningtreatment is used as such, the bonding strength between the tire frameand the tire-constituting rubber member may be enhanced by the anchoreffect. In addition, since the outer circumferential surface has beensubjected to the roughening treatment, excellent wettability of thebonding agent is provided. Accordingly, the bonding agent is held in thestate of being uniformly applied onto the outer circumferential surfaceof the tire frame, the bonding strength between the tire frame and thetire-constituting rubber member is ensured, and thus peeling between thetire frame and the tire-constituting rubber member may be suppressed.

EXAMPLES Example According to First Aspect of the Present Invention

Hereinafter, the first aspect of the present invention is described inmore detail using Examples. However, the first aspect of the presentinvention is not limited thereto.

First, tires of the Examples and the Comparative Example were formedaccording to Embodiment 1-2 described above. Here, as for the materialthat forms the tire case, materials described in the following Table 1-1were used. In addition, evaluation of physical properties of thematerial and evaluation of bonding property and tire performance of thematerial with respect to each of the Examples and the ComparativeExample was carried out in accordance with the following. In ComparativeExample 1-1, since the tire case pieces were not sufficiently bonded toeach other, the tire could not be manufactured.

<<Evaluations>>

<Tensile Characteristics>

First, regarding each of the Examples and the Comparative Example, asample was produced by injection-molding of each thermoplastic resinmaterial that was used for the tire case using a mold of 127 mm×12.7 mm(length×width) and 1.6 mm (thickness). Here, the sample of each Examplewas injection-molded at 225° C., and the sample of the ComparativeExample was injection-molded at 320° C. The mold temperature was from50° C. to 70° C. in the Examples, and was 130° C. in the ComparativeExample. Further, each of the samples was punched out, wherebydumbbell-shaped test pieces (No. 5 type test pieces) defined inJISK6251:1993 were produced.

Subsequently, by using SHIMADZU AUTOGRAPH AGS-J (5 KN) manufactured byShimadzu Corporation and setting a tensile rate to 200 mm/min, tensilemodulus of elasticity, tensile strength, and elongation at break of thetest pieces were measured.

The results are shown in the following Table 1-1.

<Bonding Property>

Regarding each of the Examples and the Comparative Example, eachthermoplastic resin material that was used for the tire case was heatedusing a heat gradient testing machine (“Type-HG-100” manufactured byToyo Seiki Kogyo Co., Ltd.) at from 150° C. to 250° C. and at a pressingpressure of 1 kgf/cm² at an interval of 10° C. for 60 seconds, wherebybonding samples having a seal size of 10 mm×25 mm were produced.

With respect to each of the produced bonding samples, by using ShimadzuAutograph AGS-J (5 KN) manufactured by Shimadzu Corporation and settinga tensile rate to 50 mm/min, a 180° peel test was performed to measurethe bonding area ratio of each of the bonding samples.

The results are shown in the following Table 1-1.

<Tire Evaluation>

—Manufacturability—

Regarding manufacturability, injection molding temperatures when thetire case was injection-molded are shown in Table 1-1.

—Tire Driving Property—

A high-speed performance test was performed on the tire of each of theExamples and the Comparative Example obtained according to Embodiment1-2 described above, on the basis of JIS D4230:1999 (high-speedperformance test B). The results are shown in the following Table 1-1.

—Shape Retention Property—

During the above high-speed performance test, the tire width before andafter running was measured and compared to calculate a deformation ratio(%). The results are shown in the following Table 1-1.

TABLE 1-1 Example Example Example Comparative 1-1 1-2 1-3 Example 1-1Tire case Resin kind PAE PAE PAE PPS Product name UBESTA UBESTA UBESTAFORTRON Grade 9048X1 9055X1 9063X1 022A9 Melting point (° C.) 154 162174 279 Evaluation Tensile Tensile modulus of 183 303 626 >1000character- elasticity (MPa) istics Tensile strength 32 41 44 79 (MPa)Elongation at 400 350 250 20 break (%) Bonding 160° C. 0 0 0 0 property170° C. 0 0 0 0 [bonding 180° C. 0 0 0 0 area 190° C. 50 0 0 0 ratio(%)] 200° C. 100 70 0 0 210° C. 100 100 0 0 220° C. 100 100 10 0 230° C.100 100 100 0 240° C. 100 100 100 0 250° C. 100 100 100 0 Manufactur-Injection molding 250 250 250 340 ability property (° C.) Tire runningproperty Completion Completion Completion — Running Shape retention <1%0 0 — performance property (%) PAE: polyamide-based thermoplasticelastomer PPS: polyphenylene sulfide resin UBESTA: manufactured by UbeIndustries, Ltd. FORTRON: manufactured by Polyplastics Co., Ltd.

As seen from Table 1-1, in the Examples in which the polyamide-basedelastomer was used, all of the tensile modulus of elasticity, thetensile strength, and the breaking elongation of the tire case had agood value for the performance required for a tire. In contrast, in thetire case of Comparative Example 1-1, the tensile modulus of elasticitywas overly high, and moreover, good results could not be obtained withrespect to the breaking elongation.

In addition, regarding bonding property, it is seen that 100% bondingcould be made at from around 200° C. to 230° C. In contrast, the meltingpoint of PPS used in Comparative Example 1-1 was so high that bonding ofthe tire case could not sufficiently be made at 250° C.

Furthermore, in Examples 1-1 to 1-3, the injection molding temperaturewas about 250° C. and therefore injection molding property wasexcellent, and running performance including tire running property andshape retention property was sufficient.

Examples According to Second Aspect of the Present Invention

Hereinafter, the second aspect of the present invention is described inmore detail using Examples. However, the second aspect of the presentinvention is not limited thereto.

First, tires of the Examples and the Comparative Examples were formedaccording to Embodiment 2-2 described above. Here, as for thematerial(s) that forms the tire case, materials described in thefollowing Table 2-1 were used. In addition, evaluation of the physicalproperties of the material and evaluation of bonding property and tireperformance of the material with respect to each of the Examples and theComparative Examples was carried out in accordance with the following.

<Production of Test Pieces>

1. Polyamide-based thermoplastic elastomer

-   -   UBESTA, XPA9055X1 (PAE1) manufactured by Ube Industries, Ltd.    -   UBESTA, XPA9063X1 (PAE2) manufactured by Ube Industries, Ltd.

2. Polyurethane-based thermoplastic elastomer

-   -   1) ELASTOLLAN, ET680 (ester-based) (TPU1) manufactured by BASF    -   2) ELASTOLLAN, ET880 (ether-based) (TPU2) manufactured by BASF    -   3) ELASTOLLAN, ET690 (ester-based) (TPU3) manufactured by BASF    -   4) ELASTOLLAN, ET890 (ether-based) (TPU4) manufactured by BASF

3. Polystyrene-based thermoplastic elastomer

-   -   1) TUFTEC, H1052 (TPS1) manufactured by Asahi Kasei Corporation

4. α-polyolefin-based thermoplastic elastomer

-   -   1) TOUGHMER, MH7007 (TPO1) manufactured by Mitsui Chemicals,        Inc.    -   2) TOUGHMER, MH7010 (TPO2) manufactured by Mitsui Chemicals,        Inc.    -   3) TOUGHMER, A4050S (TPO3) manufactured by Mitsui Chemicals,        Inc.    -   4) TOUGHMER, A1050S (TPO4) manufactured by Mitsui Chemicals,        Inc.    -   5) TOUGHMER, P275 (TPO5) manufactured by Mitsui Chemicals, Inc.    -   6) NUCREL, N035C (TPO6) manufactured by Du Pont-Toray Co., Ltd.    -   7) NUCREL, AN42115C (TPO7) manufactured by Du Pont-Toray Co.,        Ltd.

5. Polyester-based thermoplastic elastomer

-   -   1) HYTREL, 3046 (TPC) manufactured by Du Pont-Toray Co., Ltd.

The elastomers were mixed in a composition (in terms of mass) shown inTable 2-1 and were kneaded by a twin-screw extruder “LABOPLASTOMILL 50MW” manufactured by Toyo Seiki Seisaku-sho, Ltd. to obtain pellets. InComparative Examples 2-1 and 2-2, a mixed system was not used, andpellets of polyamide-based thermoplastic elastomers were provided.

Subsequently, injection molding was performed using “SE30D” manufacturedby Sumitomo Heavy Industries, Ltd. at a molding temperature of from 200°C. to 225° C. and using a mold of 12.7 mm×127 mm and having a thicknessof 1.6 mm at a mold temperature of from 50° C. to 70° C., wherebysamples of 12.7 mm×12.7 mm and having a thickness of 1.6 mm wereobtained.

Each of the samples was punched out, whereby dumbbell-shaped test pieces(No. 5 type test pieces) defined in JISK6251:1993 were produced.

<Evaluations of Tensile Strength, Elongation at Break, and TensileModulus of Elasticity>

By using Shimadzu Autograph AGS-J (5 KN) manufactured by ShimadzuCorporation and setting a tensile rate to 200 mm/min, tensile modulus ofelasticity, tensile strength, and elongation at break of each of thetest pieces were measured. The results are shown in the following Table2-1.

TABLE 2-1 Example 2-1 2-2 2-3 2-4 2-5 2-6 2-7 2-8 2-9 Tire PolyamidePAE1 PAE1 PAE1 PAE1 PAE2 PAE2 PAE1 PAE1 PAE1 case elastomer 75 75 75 7575 75 70 70 70 mass % mass % mass % mass % mass % mass % mass % mass %mass % other TPU1 TPU2 TPU3 TPU4 TPU1 TPU2 TPS1 TPO1 TPO2 monomers 25 2525 25 25 25 30 30 30 mass % mass % mass % mass % mass % mass % mass %mass % mass % Evaluation Tensile 22 13 26 16 26 22 23 29 33 strength(MPa) Elongation 200 140 180 130 130 85 405 285 235 at break(%) Tensile244 178 232 205 532 485 178 181 173 modulus of elasticity (MPa)Comparative Example Example 2-10 2-11 2-12 2-13 2-14 2-15 2-1 2-2 TirePolyamide PAE1 PAE1 PAE1 PAE1 PAE1 PAE1 PAE1 PAE2 case elastomer 70 7070 70 70 75 100 100 mass % mass % mass % mass % mass % mass % mass %mass % other TPO3 TPO4 TPO5 TPO6 TPO7 TPC1 — — monomers 30 30 30 30 3025 mass % mass % mass % mass % mass % mass % Evaluation Tensile 21 20 2327 36 37 41 44 strength (MPa) Elongation 260 250 270 320 445 345 350 250at break(%) Tensile 181 164 184 238 266 256 303 626 modulus ofelasticity (MPa)

The tires formed according to the Examples had excellent runningperformance such as impact resistance and durability. In addition, asseen from the results of Table 2-1, it is understood that elasticmodulus is low in the Examples compared to Comparative Examples in whichthe same kind of polyamide-based thermoplastic elastomer was singlyused. That is, it is understood that by using other elastomers incombination with the polyamide-based thermoplastic elastomer, theelastic modulus of the thermoplastic resin material that forms the tirecase was controlled.

<Evaluation of Pull-Out Property of Reinforcing Cord>

With respect to Examples 2-1 and 2-2 and Comparative Example 2-1, apull-out property of the reinforcing cord was evaluated as follows.

First, φ0.8 mm of a brass-plated wire and φ0.96 mm of a bronze wire werewashed with water, and were baked at 110° C. for 5 minutes. Next, forExamples 2-1 and 2-2 and Comparative Example 2-1, the thermoplasticresin materials were injection-molded with a mold in which each of theaforementioned wires was inserted to produce samples having φ10 mm.Here, as the injection molding machine, “ROBOSHOT α-15C” manufactured byFANUC Corporation was used. In the formation of the sample, each of thesamples was produced having embedment lengths of 20 mm, 40 mm, or 60 mmof wire.

As for the pull-out property of the wire from the samples, the pull-outforce (unit: N) at the time of pulling-out was measured at 5 mm/minusing “AG-5 KNK” manufactured by Shimadzu Corporation.

The results are shown in the following Table 2-2.

TABLE 2-2 φ0.8 mm brass-plated wire φ0.96 mm bronze wire Resin kind 1020 40 60 10 20 40 60 Example 2-1 PAE1 TPU1 — 455.7 877.4 938.0 — 442.11162.3 1099.6 75 25 mass % mass % Example 2-2 PAE1 TPU2 — 291.7 484.1551.0 — 348.8 935.3 986.3 75 25 mass % mass % Comparative PAE1 39.5 63.865.0 76.7 40.9 149.7 174.4 211.1 example 2-1 100%

As shown in Table 2-2, it is understood that in Examples 2-1 and 2-2 inwhich the polyurethane-based thermoplastic elastomer was used incombination, the pull-out property of the wire cord were significantlyenhanced compared to Comparative Example 2-1 in which thepolyamide-based thermoplastic elastomer was singly used.

Examples According to Third Aspect of the Present Invention

Hereinafter, the third aspect of the present invention is described inmore detail using Examples. However, the third aspect of the presentinvention is not limited thereto.

First, tires of the Examples and the Comparative Examples were formedaccording to Embodiment 3-1 described above. Here, as for the materialthat forms the tire case, materials described in the following Table 3-1were used. In addition, test pieces each of 12.7 mm×127 mm and having athickness of 1.6 mm and having the same component compositions as thoseof the tire cases formed under the same conditions as in the Examplesand the Comparative Examples were prepared, and evaluations of injectionmolding property, tensile strength, elongation at break, and breakingstate were performed. The results are shown in the following Table 3-1.In addition, the production method of each of the test pieces, theevaluation method, and the evaluation conditions are as follows.

<Production of Test Pieces>

1. Polyamide-based thermoplastic elastomer

-   -   UBESTA, XPA9055X1 manufactured by Ube Industries, Ltd.

2. α-olefin-based thermoplastic elastomer

-   -   1) TOUGHMER, MA8510 manufactured by Mitsui Chemicals, Inc.    -   2) TOUGHMER, MH7007 manufactured by Mitsui Chemicals, Inc.    -   3) TOUGHMER, MH7010 manufactured by Mitsui Chemicals, Inc.    -   4) TOUGHMER, MH7020 manufactured by Mitsui Chemicals, Inc.    -   5) TOUGHMER, A1050S manufactured by Mitsui Chemicals, Inc.

3. Styrene-based thermoplastic elastomer [fully-hydrogenated type(SEBS)]

-   -   1) TUFTEC, H1041 manufactured by Asahi Kasei Corporation    -   2) TUFTEC, M1931 manufactured by Asahi Kasei Corporation

The thermoplastic elastomers were mixed in a composition (in terms ofmass) shown in Table 3-1 and were kneaded by the twin-screw extruder“LABOPLASTOMILL 50 MR” manufactured by Toyo Seiki Seisaku-sho, Ltd. toobtain pellets. In Comparative Example 3-1, a mixed system was not used,and pellets of polyamide-based thermoplastic elastomer were provided.

Using each of the prepared pellets of the Examples and the ComparativeExample, injection molding was performed under the following conditionsto obtain test pieces.

For the injection molding, SE30D manufactured by Sumitomo HeavyIndustries, Ltd. was used, the molding temperature was set to from 200°C. to 235° C. and the mold temperature was set to from 70° C. to 80° C.,and a mold of 12.7 mm×127 mm and having a thickness of 1.6 mm was used.

Regarding the injection molding using each of the pellets in Examples3-6 and 3-8, the injection molding could not be performed under theabove conditions. Therefore each of the pellets in Examples 3-6 and 3-8was pressurized at 12 MPa for 5 minutes using an electrothermal pressmanufactured by Kodaira Seisakusho Co., Ltd., to obtain a molded productof 200 mm×200 mm and having a thickness of 2 mm.

<Measurement of Acid Value of Thermoplastic Resin Material>

The acid value of the thermoplastic resin material was calculated basedon the above equation (1) or equation (2) from the mass [mg] of sodiummethoxide (CH₃ONa) used when neutralization titration was performed oneach of the elastomers used in the Examples and the Comparative Examplesusing sodium methoxide (CH₃ONa). The results are shown in Table 3-1.

<Evaluation Method>

1. Evaluation of Fluidity [MFR (g/10 Minutes, 230° C.)] and Evaluationof Injection Molding Property

A load of 21.18 N, 49.03 N, or 98.07 N was applied to each of thepellets of the Examples and the Comparative Examples based on ASTM A1238(B method) using a semi-auto melt indexer 2A type manufactured by ToyoSeiki Seisaku-sho, Ltd. to measure fluidity (MFR). Measurement wasstarted from a small load (21.18 N), and in a case in which MFR couldnot be measured under this condition, a higher load was applied formeasurement. After starting measurement, those for which measurement didnot start even after 3 minutes elapsed were indicated by “-” in Table3-1.

In addition, evaluation of injection molding property under theconditions of a molding temperature of from 200° C. to 235° C. and amold temperature of from 70° C. to 80° C. was performed using the abovedescribed SE30D manufactured by Sumitomo Heavy Industries, Ltd., and theresults are shown in Table 3-1. Those that could not be injection-moldedunder the corresponding conditions were indicated by O, and those thatcould be injection-molded under the corresponding conditions wereindicated by Δ, in Table 3-1.

2. Evaluations of Tensile Strength, Elongation at Break, Tensile Modulusof Elasticity, and Breaking State

The test pieces obtained by the injection molding were punched out,whereby dumbbell-shaped test pieces (No. 5 type test pieces) defined inJISK6251-1993 were produced.

By using Shimadzu Autograph AGS-J (5 KN) manufactured by ShimadzuCorporation and pulling the dumbbell-shaped test pieces at a tensilerate of 200 mm/min, tensile strength, elongation at break, tensilemodulus of elasticity, and breaking state of the test pieces wereexamined.

The breaking state was evaluated by visually observing a cross-sectionof the test piece based on the following evaluation criteria.

—Evaluation Criteria—

O: the test piece was broken due to ductile fracture.

Δ: the test piece was broken due to laminar-shaped fracture.

X: the test piece was broken due to brittle fracture.

2. SEM Photograph Observation

Cross-sections of the test pieces of Examples 3-1 and 3-8 andComparative Example 3-3 were observed with a scanning electronmicroscope S-4300 manufactured by Hitachi, Ltd., and the obtained SEMphotographs are respectively shown in FIGS. 7, 8 and 9.

TABLE 3-1 Comparative Example Example 3-1 3-2 3-3 3-1 3-2 3-3 3-4 3-53-6 3-7 3-8 Polyamide UBESTA XPA 100 70 70 70 70 70 70 70 70 70 70elastomer 9055X α-olefin- TOUGHMER MA8510 30 based MH7007 30 elastomerMH7010 30 15 20 MH7020 30 A1050S 30 15 10 Styrene- TUFTEC H1041 30 15based M1913 15 30 elastomer (SEBS) Acid value of thermoplastic resin 0 00 1.11 0.78 1.11 0.56 0.74 2.22 1.5 3 [mg-CH₃ONa/g] Evaluation MFR load21.18 N 20.1 14.62 26.63 — — — — — — — — MFR load 49.03 N — 4.12 — 8.974.19 — — — MFR load 98.07 N 8.23 5.43 — — — Injection molding ◯ ◯ ◯ ◯ ◯◯ ◯ ◯ Δ ◯ Δ property Tensile strength 41 20 32 33 29 33 34 31 35 36 32[MPa] Elongation at break 350 250 425 265 285 275 325 275 475 300 425[%] Tensile modulus of 303 164 227 198 181 173 195 194 156 254 227elasticity [MPa] Breaking state ◯ Δ Δ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯

As seen from Table 3-1, the test pieces described in Examples 3-1 to 3-8were able to achieve both reduction in tensile modulus of elasticity andfracture property. Therefore, it is apparent that the tire manufacturedusing the tire case formed using the same thermoplastic resin materialsas those of the test pieces described in Examples 3-1 to 3-8 couldachieve both reduction in tensile modulus of elasticity and fractureproperty. Therefore, it is assumed that a vehicle configured using sucha tire has good ride quality and even when tire is damaged, the tire isless likely to burst and break.

In addition, a high-speed performance test was performed on each of thetires formed in the Examples and the Comparative Examples based on JISD4230-1999 (high-speed performance test B), and all of the tirescompleted the course and there was no problem in safety during running.

In addition, from the SEM photographs (FIGS. 7 and 8) of the test piecesused in Examples 3-1 and 3-8, it is understood that the island phase ofthe acid-modified part of the acid-modified elastomer was finelydispersed in the resin. In contrast, referring to the SEM photograph(FIG. 9) of the test piece used in Comparative Example 3-3, it isunderstood that the large dark phase (polystyrene-based thermoplasticelastomer) was present in the pale matrix (polyamide-based thermoplasticelastomer). It is considered that the polystyrene-based thermoplasticelastomer used in Comparative Example 3-3 was not acid-modified, wasdifficult to be mixed with the polystyrene-based thermoplasticelastomer, and therefore had not equaled the Examples in terms offracture property.

As such, it was proved from the SEM photographs that the test piecesused in Examples 3-1 and 3-8 had excellent tensile elasticity andfracture property.

Examples According to Fourth Aspect of the Present Invention

Hereinafter, the fourth aspect of the present invention is described inmore detail using Examples. However, the fourth aspect of the presentinvention is not limited thereto.

First, tires of the Examples and the Comparative Examples were formedaccording to Embodiment 4-1 described above. Here, as for the materialthat forms the tire case, materials described in the following Table 4-1were used.

In addition, test pieces each having the same component compositions asthose of the tire cases formed under the same conditions as in theExamples and the Comparative Examples were prepared, and the evaluationsof tensile strength, elongation at break, tensile modulus of elasticity,breaking state, and tan δ were performed. The production method of eachof the test pieces, each of the evaluation methods, and the evaluationconditions are as follows.

[Production of Pellets]

<Thermoplastic Elastomer or Thermoplastic Resin for Comparison>

-   -   (1) Polyamide-based thermoplastic elastomer        -   1) UBESTA XPA9048X1 manufactured by Ube Industries, Ltd.        -   2) UBESTA XPA9055X1 manufactured by Ube Industries, Ltd.    -   (2) Polyester-based thermoplastic elastomer        -   1) HYTREL 5557 manufactured by Du Pont-Toray Co., Ltd.    -   (3) Thermoplastic resin for comparison        -   1) SBR1500 manufactured by JSR Corporation

<Specific Needle-Shaped Crystal Particles>

-   -   (1) Magnesium sulfate particles (whisker)        -   1) “MOS-HIGE”, fiber length: 1.0 μm to 3.0 μm, fiber            diameter: 0.5 μm to 1.0 μm, manufactured by Ube Material            Industries, Ltd.

<Particles for Comparison>

-   -   (1) Carbon black (“#78”, spherical concatenated fine particles,        manufactured by Asahi Carbon Co., Ltd.)

The materials selected from the materials described above wereintroduced into a twin-screw extruder “LABOPLASTOMILL 50 MR”manufactured by Toyo Seiki Seisaku-sho, Ltd. at the composition shown inTable 4-1 (in terms of mass) and were kneaded under the followingkneading conditions to obtain pellets. In Comparative Examples 4-1 to4-3, kneading was not performed, and pellets of each of thermoplasticelastomers were prepared.

—Kneading Conditions—

-   -   screw revolutions: 100 rpm    -   screw length (L)/screw diameter (D): 45    -   kneading temperature: 200° C.    -   kneading time: 12 minutes

[Production of Resin Plate]

A resin plate having a thickness of 2 mm, a width of 30 mm, and a lengthof 100 mm was molded using the obtained pellets as a molding material bysetting a molding temperature (cylinder temperature) to 180° C. to 230°C. and a mold temperature to 60° C., with an injection molding machine(an injection molding machine SE30D manufactured by Sumitomo HeavyIndustries, Ltd.).

[1. Evaluations of Tensile Strength and Tensile Modulus of Elasticity]

(1) Production of Test Pieces

The dumbbell-shaped test pieces (No. 5 type test pieces) defined inJISK6251-1993 were punched out from the produced resin plates, toproduce test pieces for evaluation.

(2) Evaluation

The obtained dumbbell-shaped test pieces were pulled at a tensile rateof 200 mm/min using Shimadzu Autograph AGS-J (5 KN) manufactured byShimadzu Corporation, to evaluate tensile modulus of elasticity andtensile strength of the test pieces. Tensile modulus of elasticity andtensile strength in both cases in which the test pieces for evaluationwere heated to 30° C. and 80° C. were evaluated. Heating of the testpieces was performed by controlling temperature using a temperaturecontrol chamber in a viscoelasticity measurement device.

The results are shown in Table 4-1.

[2. Measurement of Tan δ]

(1) Production of Test Pieces

The produced resin plates were punched so as to have circular shapeshaving a diameter of 6 mm, to produce test pieces for evaluation.

(2) Evaluation

Regarding the produced test pieces for evaluation, by using a dynamicviscoelasticity measurement test machine “ARES III” manufactured byRheometric Scientific, Inc., a loss tangent (tan δ) was measured at atemperature of 30° C., a measurement frequency of 35 Hz, and a dynamicstrain of 1%.

The results are shown in Table 4-1.

TABLE 4-1 Example Example Example Example Example Example 4-1 4-2 4-34-4 4-5 4-6 Thermo- Thermoplastic Polyamide-based UBESTA XPA 9048X1 100100 plastic elastomer or elastomer XPA 9055X1 100 100 resin resin forPolyester-based HYTREL 5557 100 material comparison elastomerPolystyrene-based SEBS H1062 100 elastomer Styrene-butadiene SBR 1500rubber Specific needle- Magnesium sulfate whisker 0.5 0.5 1 1 1 1 shapedcrystal particles Particles for Carbon black comparison EvaluationTensile modulus of elasticity (MPa) 30° C. 224 335 245 384 285 121Tensile strength (MPa) 30° C. 33 37 34 38 32 28 Tensile modulus ofelasticity (MPa) 80° C. 120 208 125 215 162 102 Tensile strength (MPa)80° C. 18 19 18 21 16 18 Loss factor (tanδ) 0.055 0.1 0.054 0.11 0.060.07 Com- Com- Com- Com- Com- Compara- Compara- para- para- para- para-para- tive tive tive tive tive tive tive Example Example Exam- Exam-Exam- Exam- Exam- 4-1 4-2 ple 4-3 ple 4-4 ple 4-5 ple 4-6 ple 4-7Thermo- Thermoplastic Polyamide-based UBESTA XPA 9048X1 100 100 100plastic elastomer or elastomer XPA 9055X1 100 resin resin forPolyester-based HYTREL 5557 100 material comparison elastomerPolystyrene-based SEBS H1062 100 elastomer Styrene-butadiene SBR 1500100 rubber Specific needle- Magnesium sulfate whisker 0 0 0 0 shapedcrystal particles Particles for Carbon black 15 1 15 comparisonEvaluation Tensile modulus of elasticity (MPa) 30° C. 198 299 210 68 543174 421 Tensile strength (MPa) 30° C. 32 34 30 24 45 14 31 Tensilemodulus of elasticity (MPa) 80° C. 105 158 123 44 268 88 198 Tensilestrength (MPa) 80° C. 18 22 19 14 27 9 14 Loss factor (tanδ) 0.055 0.110.05 0.06 0.16 0.08 0.22

As shown in Table 4-1, it is understood that in each of the test piecesof the Examples, all the evaluations of tensile modulus of elasticity,tensile strength, and loss factor (tan δ) were good compared to each ofthe test pieces of the Comparative Examples.

Therefore, it is understood that the tires produced using the samethermoplastic resin materials as those of the test pieces described inthe Examples has excellent steering stability and suppressed rollingresistance, and that a vehicle equipped with the tire has excellentsteering stability and exhibits low fuel consumption.

In addition, a drum running test was performed on each of the tiresformed using the thermoplastic resin materials of each of the Examplesand the Comparative Examples, and all of the tires had no problems instability during running.

Examples According to Fifth Aspect of the Present Invention

Hereinafter, the fifth aspect of the present invention is described inmore detail using Examples. However, the fifth aspect of the presentinvention is not limited thereto.

First, tires of the Examples and Comparative the Examples were formedaccording to Embodiment 5-2 described above. Here, as for the materialthat forms the tire case, materials described in the following Table 5-1were used. Evaluations of physical properties and tire performance withrespect to each of the Examples and the Comparative Examples wereperformed as follows.

[Production of Pellets]

Regarding the resin materials used for the tire case in each of theExamples and the Comparative Examples, the materials were mixed in acomposition (in terms of mass) shown in Table 5-1. Subsequently, theresin materials were kneaded (a mixing temperature of 230° C. and akneading time period of 3 minutes) with a twin-screw extruder“LABOPLASTOMILL 50 MR” manufactured by Toyo Seiki Seisaku-sho, Ltd. toobtain pellets. In some of the Comparative Examples, a mixed system wasnot used, and pellets of polyamide-based thermoplastic elastomers wereprovided.

<Evaluations of Loss Factor (Tan δ) and Tensile Modulus of Elasticity>

Injection molding was performed using the produced pellets with SE30Dmanufactured by Sumitomo Heavy Industries, Ltd. at a molding temperatureof from 180° C. to 260° C. and at a mold temperature of from 50° C. to70° C., to obtain samples each of 100 mm×30 mm and having a thickness of2.0 mm.

Each of the samples was punched out, whereby dumbbell-shaped test pieces(No. 5 type test pieces) defined in JISK6251:1993 were produced.

Subsequently, by using Shimadzu Autograph AGS-J (5 KN) manufactured byShimadzu Corporation and setting a tensile rate to 200 mm/min, tensilemodulus of elasticity at 30° C. and 80° C. and tan δ of each of thedumbbell-shaped test pieces were measured. The results are shown inTable 5-1.

TABLE 5-1 Example Example Example Example Comparative ComparativeComparative 5-1 5-2 5-3 5-4 Example 5-1 Example 5-2 Example 5-3 TireThermoplastic PA-A PA-B PA-A PA-A PA-A PA-B PA-A case elastomer Tg/° C.of 41 41 41 41 41 41 41 hard polymer Tensile 198 299 198 198 198 299 198modulus of elasticity/ Mpa Loss factor 0.06 0.1 0.06 0.06 0.06 0.1 0.06(tanδ) Specific PPE PPE ABS AES — — PP resin Tg/° C. 210 210 118 127 — —0 Tensile 1150 1150 1373 1665 — — 1200 modulus of elasticity/ Mpa Lossfactor 0.03 0.03 0.1 0.06 — — 0.12 (tanδ) Mass ratio 85/15 88/12 70/3070/30 — — 85/15 (X + Y)/Z Evaluation Tensile 225 334 369 355 198 299 181modulus of elasticity/ 30° C. Tensile 106 121 183 175 89 158 78 modulusof elasticity/ 80° C. Tensile 48 62 19 17 39 54 23 strength/ Mpa Lossfactor 0.05 0.09 0.06 0.06 0.06 0.1 0.14 (tanδ)

-   -   In Table 5-1, “mass ratio(x+y)/z” represents the mass ratio of        the total amount of the hard segment of the thermoplastic        elastomer and the specific resin according to the fifth aspect        of the present invention to the total amount of the soft        segment.

Description of the abbreviations in the above Table 5-1 is provided asfollows.

-   -   PA-A: polyamide-based thermoplastic elastomer (“UBESTA        XPA9048X1” manufactured by Ube Industries, Ltd., a        polyamide-content ratio of 40% by weight)    -   PA-B: polyamide-based thermoplastic elastomer (“UBESTA        XPA9055X1” manufactured by Ube Industries, Ltd., a        polyamide-content ratio of 50% by weight)    -   PPE: polyphenylene ether    -   (“XYRON 200H” manufactured by Asahi Kasei Chemicals Corporation)    -   PP: polypropylene    -   (“NOVATEC BC3H” manufactured by Japan Polypropylene Corporation)    -   ABS: acrylonitrile/butadiene/styrene copolymer    -   (“TECHNO ABS 170” manufactured by Technopolymer Co., Ltd.)    -   AES: acrylonitrile/ethylene/styrene copolymer    -   (“W245” manufactured by Technopolymer Co., Ltd.)

As seen from Table 5-1, it is understood that, the materials for thetire case of Examples 5-1 to 5-4 had improved tensile modulus ofelasticity while low loss factor (tan δ) was maintained, compared tothose of the Comparative Examples. In addition, it is understood that,in the materials for the tire case of Examples 5-1 to 5-4, the tensilemoduli of elasticity at 30° C. were higher than those in ComparativeExample 5-1 or 5-2 in which the same thermoplastic elastomers were used,and the tensile moduli of elasticity at 80° C. in Examples 5-1, 5-3, and5-4 were higher than that in Comparative Example 5-1, whereby heatresistance was improved.

In addition, in Comparative Example 5-3 in which the resin(polypropylene: “NOVATEC BC3H” manufactured by Japan PolypropyleneCorporation) having a lower glass-transition temperature than theglass-transition temperature of the hard segment (polyamide 12) of PA-Awas used, the tensile modulus of elasticity was not improved compared toExample 5-1, and heat resistance was low.

Moreover, the tires in the Examples had small rolling resistance andexcellent heat resistance.

Examples According to Sixth Aspect of the Present Invention

Hereinafter, the sixth aspect of the present invention is described inmore detail using Examples. However, the sixth aspect of the presentinvention is not limited thereto.

First, tires of the Examples and the Comparative Examples were formedaccording to Embodiment 6-1 described above. Here, as for the materialthat forms the tire case, materials described in the following Table 6-1were used.

In addition, test pieces having the same component compositions as thoseof the tire cases formed under the same conditions as in the Examplesand the Comparative Examples were prepared, and the evaluations oftensile strength, elongation at break, tensile modulus of elasticity,breaking state, and tan δ were performed. The production method of eachof the test pieces, each of the evaluation methods, and the evaluationconditions are as follows.

[Production of Pellets]

<Thermoplastic Elastomer>

-   -   (1) Polyamide-based thermoplastic elastomer        -   1) UBESTA XPA9055X1 manufactured by Ube Industries, Ltd.        -   2) UBESTA XPA9048X1 manufactured by Ube Industries, Ltd.    -   (2) Polyester-based thermoplastic elastomer        -   1) HYTREL 3046 manufactured by Du Pont-Toray Co., Ltd.

<Antistatic Material>

-   -   (1) Carbon black (“HAF”, manufactured by Asahi Carbon Co., Ltd.)    -   (2) Phosphoester-based ion conductive agent (“ELENITE AB-100”        manufactured by Takamatsu Oil & Fat Co., Ltd.)

The materials selected from the materials described above wereintroduced into a twin-screw extruder manufactured by TechnovelCorporation at the composition (in terms of mass) shown in Table 6-1 andwere kneaded under the following kneading conditions to obtain pellets.In Comparative Examples 6-1 to 6-3, kneading was not performed, andpellets of each of thermoplastic elastomers were provided.

—Kneading Conditions—

-   -   screw revolutions: 100 rpm    -   screw length (L)/screw diameter (D): 45    -   kneading temperature: 200° C.    -   kneading time: 12 minutes

[Production of Resin Plates]

Heat-pressing was performed using the obtained pellets as moldingmaterials and using an electrothermal press manufactured by KodairaSeisakusho Co., Ltd. by heating at 230° C. and 12 MPa for 5 minutes, toproduce a resin plate having a length of 80 mm, a width of 40 mm, and athickness of 2 mm.

[1. Measurement of Volume Resistivity]

As the resin plates obtained as above as test pieces for evaluation,volume resistivity was measured using a resistivity meter “HIRESTA UPMCP-HT450 type” manufactured by Mitsubishi Chemical Analytech Co., Ltd.according to JIS K6911:(in 1995).

The volume resistivity that is equal to or less than 10¹⁰ Ω·cm is not apractically problematic level for the tire to exhibit antistaticperformance.

The results are shown in Table 6-1.

[2. Evaluations of Tensile Strength, Elongation at Break, TensileModulus of Elasticity, and Fracture Property]

(1) Production of Test Pieces

The dumbbell-shaped test pieces (No. 5 type test pieces) defined inJISK6251-1993 were punched out from the produced resin plates, toproduce test pieces for evaluation.

(2) Evaluation

By pulling the obtained dumbbell-shaped test pieces at a tensile rate of200 mm/min using Shimadzu Autograph AGS-J (5 KN) manufactured byShimadzu Corporation, tensile strength, elongation at break, tensilemodulus of elasticity, and breaking state (fracture property) of thetest pieces were examined.

The results are shown in Table 6-1.

The fracture property was evaluated by visually observing a breakingstate of a cross-section of the test piece based on the followingevaluation criteria.

—Evaluation Criteria—

O: the test piece was broken due to ductile fracture.

Δ: the test piece was broken due to laminar-shaped fracture.

x: the test piece was broken due to brittle fracture.

[2. Measurement of Tan δ]

(1) Production of Test Pieces

The produced resin plates were punched out so as to have circular shapeshaving a diameter of 6 mm, to produce test pieces for evaluation.

(2) Evaluation

Regarding the produced test pieces for evaluation, by using a dynamicviscoelasticity measurement test machine “ARES III” manufactured byRheometric Scientific, Inc., a loss tangent (tan δ) was measured at atemperature of 30° C., a measurement frequency of 35 Hz, and a dynamicstrain of 1%.

The results are shown in Table 6-1.

TABLE 6-1 Example Example Example Example Example Example 6-1 6-2 6-36-4 6-5 6-6 Thermo- Thermo- Polyamide UBESTA XPA9055X1 100 100 plasticplastic elastomer XPA9048X1 100 100 100 100 resin elastomer materialPolyester HYTREL 5557 elastomer Antistatic Carbon HAF 5 10 materialblack Phospho- ELENITE AB-100 5 10 5 10 ester- based ion conductiveagent Evaluation Volume resistivity (Ω · cm) 3.7 × 10⁹ 6.3 × 10⁸ 2.1 ×10⁹ 6.5 × 10⁸ 4.5 × 10⁹ 2.1 × 10⁷ Tensile modulus of elasticity (MPa)201 195 299 305 224 238 Tensile strength (MPa) 28 27 32 31 34 36Elongation at break (%) 480 510 520 550 380 360 Fracture property ◯ ◯ ◯◯ ◯ ◯ tanδ 0.059 0.061 0.1 0.11 0.078 0.16 Comparative ComparativeComparative Example Example Example Example 6-7 6-1 6-2 6-3 Thermo-Thermo- Polyamide UBESTA XPA9055X1 100 plastic plastic elastomerXPA9048X1 100 resin elastomer material Polyester HYTREL 5557 100 100elastomer Antistatic Carbon HAF 0 0 0 material black Phospho- ELENITEAB-100 10 0 0 0 ester- based ion conductive agent Evaluation Volumeresistivity (Ω · cm) 8.8 × 10⁸ 3.1 × 10¹² 6.3 × 10¹¹ 2.2 × 10¹¹ Tensilemodulus of elasticity (MPa) 128 203 302 131 Tensile strength (MPa) 29 3334 33 Elongation at break (%) 430 460 520 410 Fracture property ◯ ◯ ◯ ◯tanδ 0.12 0.06 0.1 0.14

As shown in Table 6-1, from each of the test pieces of the Exampleshaving a volume resistivity being in a range of from 1.0×10⁶ to 1.0×10¹⁰compared to each of the test pieces of the Comparative Examples, it isunderstood that the tire produced using the same thermoplastic resinmaterials as those of the test pieces has excellent antistaticperformance.

In addition, in each of the test pieces of Examples 6-1 to 6-7, thevolume resistivity thereof was in a range of from 1.0×10⁶ to 1.0×10¹⁰,and tan δ was also maintained at a low level. Therefore, the tireproduced using the same thermoplastic resin materials as those of thetest pieces described in Examples 6-1 to 6-7 has excellent antistaticperformance, and suppressed the rolling resistance. Therefore, it isperceived that a vehicle including such a tire suppresses moreeffectively generation of discharge caused by electrification andadhesion of fine dust or the like to the surface of the tire, hasexcellent steering stability, and exhibits low fuel consumption.

In addition, a drum running test was performed on each of the tiresformed using the thermoplastic resin materials of each of the Examplesand the Comparative Examples, and all of the tires had no problems instability during running.

Examples According to Seventh Aspect of the Present Invention

Hereinafter, the seventh aspect of the present invention is described inmore detail using Examples. However, the seventh aspect of the presentinvention is not limited thereto.

First, tires of the Examples and the Comparative Examples were formedaccording to Embodiment 7-1 described above. Here, as for the materialthat forms the tire case, materials described in the following Tables7-1 and 7-2 were used. Test pieces each of 12.7 mm×127 mm and having thesame component compositions as those of the tire cases formed under thesame conditions as in the Examples and the Comparative Examples and wereproduced, and injection molding property, tensile strength, elongationat break, tensile modulus of elasticity, and breaking state wereevaluated. The production method of each of the test pieces, theevaluation method, and the evaluation conditions are as follows.

<Production of Test Pieces>

A-1. Polyamide-Based Thermoplastic Elastomer

-   -   1) UBESTA, XPA9040X1 manufactured by Ube Industries, Ltd.    -   2) UBESTA, XPA9048X1 manufactured by Ube Industries, Ltd.    -   3) UBESTA, XPA9055X1 manufactured by Ube Industries, Ltd.    -   4) UBESTA, XPA9063X1 manufactured by Ube Industries, Ltd.

A-2. Polyamide-Based Thermoplastic Resin (the Same Kind of Resin as theHard Segment of A-1)

-   -   1) UBESTA, 3014U manufactured by Ube Industries, Ltd.    -   2) UBESTA, 3020U manufactured by Ube Industries, Ltd.

B-1) Polyester-Based Thermoplastic Elastomer

-   -   1) HYTREL 3046 manufactured by Du Pont-Toray Co., Ltd.    -   2) HYTREL 5557 manufactured by Du Pont-Toray Co., Ltd.    -   3) HYTREL 6347 manufactured by Du Pont-Toray Co., Ltd.    -   4) HYTREL 7247 manufactured by Du Pont-Toray Co., Ltd.    -   5) HYTREL 2751 manufactured by Du Pont-Toray Co., Ltd.

B-2) Polybutylene Terephthalate-Based Thermoplastic Resin (the Same Kindof Resin as the Hard Segment of B-1)

-   -   1) DURANEX 2000 manufactured by Polyplastics Co., Ltd.    -   2) DURANEX 2002 manufactured by Polyplastics Co., Ltd.

—Elastic Modulus of Particular Resin According to Seventh Aspect of thePresent Invention—

Various kinds of resin described in A-2 and B-2 were injection-moldedwith a mold of 12.7 mm×127 mm and having a thickness of 1.6 mm toproduce samples.

By using Shimadzu Autograph AGS-J (5 KN) manufactured by ShimadzuCorporation and pulling the obtained samples at a tensile rate of 1mm/min, tensile modulus of elasticity of the sheet was examined, and thefollowing results were obtained.

A-2)

-   -   1) UBESTA, 3014U, manufactured by Ube Industries, Ltd., elastic        modulus=1100 MPa    -   2) UBESTA, 3020U, manufactured by Ube Industries, Ltd., elastic        modulus=1000 MPa

B-2)

-   -   1) DURANEX, 2000 manufactured by Polyplastics Co., Ltd., elastic        modulus=1100 MPa    -   2) DURANEX, 2002 manufactured by Polyplastics Co., Ltd., elastic        modulus=1250 MPa

The thermoplastic elastomers and the resins were mixed in a composition(in terms of mass) shown in Tables 7-1 and 7-2 and were kneaded with atwin-screw extruder LABOPLASTOMILL 50 MR manufactured by Toyo SeikiSeisaku-sho, Ltd. to obtain pellets. In Comparative Examples 7-1 to 7-9,a mixed system was not used, and pellets of thermoplastic elastomersshown in Tables 7-1 and 7-2 were provided.

Using each of the prepared pellets of the Examples and the ComparativeExamples, injection molding was performed under the following conditionsto obtain test pieces.

For the injection molding, SE30D manufactured by Sumitomo HeavyIndustries, Ltd. was used, the molding temperature was set to from 200°C. to 235° C. and the mold temperature was set to from 50° C. to 70° C.,and a mold of 12.7 mm×127 mm and having a thickness of 1.6 mm was used.

<Evaluation Method>

1. Evaluations of Tensile Strength, Elongation at Break, and TensileModulus of Elasticity

The test pieces obtained by the injection molding were punched out,whereby dumbbell-shaped test pieces (No. 5 type test pieces) defined inJISK6251:1993 were produced.

By using Shimadzu Autograph AGS-J (5 KN) manufactured by ShimadzuCorporation and pulling the obtained dumbbell-shaped test pieces at atensile rate of 200 mm/min, tensile strength, elongation at break, andtensile modulus of elasticity of the test pieces were examined.

2. Measurement of Tan δ

By using a dynamic viscoelasticity measurement test machine “ARES III”manufactured by Rheometric Scientific, Inc., a loss tangent (tan δ) wasmeasured at a temperature of 30° C., a measurement frequency of 20 Hz,and a dynamic strain of 1%.

The tensile strength, the elongation at break, the tensile modulus ofelasticity, and the tan δ of the test pieces of the Examples and theComparative Examples are shown in Tables 7-1 and 7-2.

3. Relationship Between Elastic Modulus (Tensile Modulus of Elasticity)and Tan δ

The relationship between the tensile modulus of elasticity and tan δ ofthe test pieces of Examples 7-1 to 7-4 and Comparative Examples 7-1 to7-4 was plotted in FIG. 11. In addition, the relationship between thetensile modulus of elasticity and tan δ of the test pieces of Examples7-5 to 7-8 and Comparative Examples 7-5 to 7-9 was plotted in FIG. 12.

TABLE 7-1 Comparative Example Example 7-1 7-2 7-3 7-4 7-1 7-2 7-3 7-4A-1 Polyamide- UBESTA XPA9040X1 100 based XPA9048X1 75 50 75 50 100elastomer XPA9055X1 100 XPA9063X1 100 A-2 Nylon 12 UBESTA 3014U 25 503020U 25 50 Evaluation Tensile strength 33 40 31 37 27 32 41 44 (MPa)Elongation at break 360 360 340 280 610 400 350 250 (%) Tensile modulusof 368 672 392 666 91 183 303 626 elasticity (MPa) tanδ 0.074 0.0880.068 0.075 0.044 0.067 0.121 0.138

TABLE 7-2 Example Comparative Example 7-5 7-6 7-7 7-8 7-5 7-6 7-7 7-87-9 B-1 Polyester- HYTREL 3046 75 50 75 50 100  based 5557 100 elastomer6347 100 7247 100 2751 100 B-2 Polyester DURANEX 2000 25 50 resin 200225 50 Evaluation Tensile strength (MPa) 18 27 15 22 17 26 27 33 37Elongation at break (%) 465 365 430 310 800< 370 310 310 320 Tensilemodulus of 171 680 90 594 19 211 414 549 1110 elasticity (MPa) tanδ0.054 0.057 0.051 0.061    0.046 0.072 0.136 0.147 0.283

As seen from Table 7-1, in the test pieces described in Examples 7-1 to7-4, even when the tensile modulus of elasticity is increased to 368 to672, tan δ that is the index representing the rolling resistance of thetire is from around 0.07 and is 0.088 at the maximum, and increase inthe rolling resistance is suppressed. Similarly, in the test pieces ofExamples 7-5 to 7-8, even when the tensile modulus of elasticity isincreased, increase in the tan δ is suppressed.

This is also understood from FIGS. 11 and 12. In FIGS. 11 and 12, tan δwith respect to tensile modulus of elasticity is plotted. As shown inFIG. 11, it is understood that a regression line (not shown) perceivedfrom the plot of Comparative Examples 7-1 to 7-4 has a great slope, andtan δ thereof is increased as the tensile modulus of elasticity isincreased, while a regression line (not shown) perceived from the plotof Examples 7-1 to 7-4 has a small slope, and tan δ thereof is lesslikely to increase even when the tensile modulus of elasticity isincreased. Similar cases are confirmed from each of the plots ofComparative Examples 7-5 to 7-9 and Examples 7-5 to 7-8 shown in Table7-2.

Therefore, it is apparent that the tire manufactured using the tire caseformed using the same thermoplastic resin materials as those of the testpieces of Examples 7-1 to 7-8 is able to suppress increase in rollingresistance even when the tensile modulus of elasticity is increased.Therefore, it is assumed that a vehicle configured using such a tire hasgood fuel efficiency.

In addition, a drum running test was performed on each of the tiresformed using the thermoplastic resin materials of each of the Examplesand the Comparative Examples, and all of the tires had no problems instability during running.

Examples According to Eighth Aspect of the Present Invention

Hereinafter, the eighth aspect of the present invention is described inmore detail using Examples. However, the eighth aspect of the presentinvention is not limited thereto.

First, tires of the Examples and the Comparative Examples were formedaccording to Embodiment 8-1 described above. Here, as for the materialthat forms the tire case, materials described in the following Tables8-1 and 8-2 were used. Test pieces each of 12.7 mm×127 mm and having thesame component compositions as those of the tire cases formed under thesame conditions as in the Examples and the Comparative Examples wereprepared, and tensile strength, elongation at break, tensile modulus ofelasticity, and breaking state were evaluated. The results are shown inTables 8-1 and 8-2. The production method of each of the test pieces,the evaluation method, and the evaluation conditions are as follows.

<Production of Test Pieces>

1. Polyamide-Based Thermoplastic Elastomer

-   -   1) UBESTA, XPA9040 manufactured by Ube Industries, Ltd.        -   (a glass-transition temperature of equal to or less than            −40° C., an elastic modulus of 91 MPa)    -   2) UBESTA, XPA9048 manufactured by Ube Industries, Ltd.        -   (a glass-transition temperature of −6° C., an elastic            modulus of 183 MPa)    -   3) UBESTA, XPA9055 manufactured by Ube Industries, Ltd.        -   (a glass-transition temperature of 8° C., an elastic modulus            of 303 MPa)    -   4) UBESTA, XPA9063 manufactured by Ube Industries, Ltd.        -   (a glass-transition temperature of 14° C., an elastic            modulus of 626 MPa)

2. Polyester-Based Thermoplastic Elastomer

-   -   1) HYTREL, 3046 manufactured by Du Pont-Toray Co., Ltd.        -   (a glass-transition temperature of −38° C., an elastic            modulus of 19 MPa)    -   2) HYTREL, 5557 manufactured by Du Pont-Toray Co., Ltd.        -   (a glass-transition temperature of −19° C., an elastic            modulus of 211 MPa)    -   3) HYTREL, 6347 manufactured by Du Pont-Toray Co., Ltd.        -   (a glass-transition temperature of 9° C., an elastic modulus            of 414 MPa)    -   4) HYTREL, 7247 manufactured by Du Pont-Toray Co., Ltd.        -   (a glass-transition temperature of 21° C., an elastic            modulus of 549 MPa)

3. Acid-Modified Polyolefin

-   -   1) ADMER QF551 manufactured by Mitsui Chemicals, Inc.        -   (a glass-transition temperature of −13° C., an elastic            modulus of 694 MPa)    -   2) ADMER QE060 manufactured by Mitsui Chemicals, Inc.        -   (a glass-transition temperature of 4° C., an elastic modulus            of 875 MPa)

4. Polypropylene, Ethylene-Propylene Copolymer

-   -   1) J-700 GP (homopolymer) manufactured by Prime Polymer Co.,        Ltd.        -   (a glass-transition temperature of 32° C., an elastic            modulus of 1244 MPa)    -   2) NOVATEC EC9EV (block polymer) manufactured by Japan        Polypropylene Corporation        -   (a glass-transition temperature of 15° C., an elastic            modulus of 1176 MPa)    -   3) WINTEC WFW4 (random polymer) manufactured by Japan        Polypropylene Corporation        -   (a glass-transition temperature of 6° C., an elastic modulus            of 762 MPa)

The thermoplastic elastomers were mixed in a composition (in terms ofmass) shown in Tables 8-1 and 8-2 and were kneaded with a twin-screwextruder LABOPLASTOMILL 50 MR manufactured by Toyo Seiki Seisaku-sho,Ltd. to obtain pellets. In Comparative Examples 8-1 to 8-8, a mixedsystem was not used, and pellets of polyamide-based thermoplasticelastomers and polyester-based thermoplastic elastomers were provided.

Using each of the prepared pellets of the Examples and the ComparativeExamples, injection molding was performed under the following conditionsto obtain test pieces.

For the injection molding, SE30D manufactured by Sumitomo HeavyIndustries, Ltd. was used, the molding temperature was set to from 200°C. to 225° C. and the mold temperature was set to from 50° C. to 70° C.,and a mold of 12.7 mm×127 mm and having a thickness of 1.6 mm was used.

<Evaluation Method>

1. Evaluations of Tensile Strength, Elongation at Break, Tensile Modulusof Elasticity, and Breaking State

Using the test pieces obtained as above, tensile strength, elongation atbreak, tensile modulus of elasticity, and breaking state were evaluatedas follows.

By using Shimadzu Autograph AGS-J (5 KN) manufactured by ShimadzuCorporation, using JIS 5 type dumbbells, and pulling the test pieces ata tensile rate of 200 mm/min, tensile strength, elongation at break,tensile modulus of elasticity, and breaking state of the test pieceswere examined.

2. Measurement of Tan δ

In addition, with respect to the test pieces obtained as above, by usingARESIII manufactured by Rheometric Scientific, Inc., tan δ was measuredunder conditions of at 30° C., 20 Hz, and a shear strain of 1%.

TABLE 8-1 Comparative Example Example 8-1 8-2 8-3 8-4 8-1 8-2 8-3 8-48-5 8-6 8-7 8-8 8-9 Polyamide-based elastomer UBESTA XPA9040 100 UBESTAXPA9048 100 70 70 70 70 70 70 70 70 70 UBESTA XPA9055 100 UBESTA XPA9063100 Acid-modified olefin QF551 30 15 15 5 15 15 QE060 30 15 15Polypropylene, ethylene-propylene copolymer J-700GP 15 15 NOVATEC EC9EV25 15 15 WINTEC WFW4 15 15 Evaluation Tensile strength 27 32 41 44 37 4443 47 31 43 39 43 41 (MPa) Elongation at break 610 400 350 250 545 585555 615 505 565 570 565 550 (%) Tensile modulus of 91 183 303 626 346500 430 546 409 389 349 400 394 elasticity (MPa) tanδ (30° C., 20 Hz,0.044 0.066 0.116 0.138 0.077 0.082 0.076 0.1 0.087 0.085 0.089 0.0890.097 1%)

TABLE 8-2 Comparative Example Example 8-5 8-6 8-7 8-8 8-10 8-11 8-128-13 8-14 8-15 8-16 Polyester-based elastomer HYTREL 3046 100  70 60 7070 70 70 70 HYTREL 5557 100 HYTREL 6347 100 HYTREL 7247 100Acid-modified olefin QF551 30 QE060 40 30 15 5 15 15 Polypropylene,ethylene-propylene copolymer J-700GP 15 NOVATEC EC9EV 25 15 WINTEC WFW415 Evaluation Tensile strength 17 26 27 33 13 14 13 12 14 15 13 (MPa)Elongation at break 800< 370 310 310 480 500 485 210 95 350 495 (%)Tensile modulus of 19 211 414 549 110 280 156 233 257 227 142 elasticity(MPa) tanδ (30° C., 20 Hz,    0.046 0.072 0.136 0.147 0.056 0.06 0.0530.067 0.058 0.061 0.063 1%)

As seen from Tables 8-1 and 8-2, in the test pieces of the Examples,tensile modulus of elasticity could be in a preferable range whilesuppressing increase in tan δ, compared to the Comparative Examples.Therefore, it is apparent that the tire manufactured using the tire caseformed using the same resin materials as those of the test pieces of theExamples obtains suitable tensile modulus of elasticity and is able tosuppress increase in rolling resistance. Therefore, it is assumed that avehicle configured using such a tire has good ride quality.

In addition, a drum running test was performed on each of the tiresformed according to the Examples and the Comparative Examples, and allof the tires had no problems in stability during running.

Examples According to Ninth Aspect of the Present Invention

Hereinafter, the ninth aspect of the present invention is described inmore detail using Examples. However, the ninth aspect of the presentinvention is not limited thereto.

First, tires of the Examples and the Comparative Examples were formedaccording to Embodiment 9-1 described above. Here, as for the materialthat forms the tire case, materials described in the following Table 9-1were used. Test pieces each of 12.7 mm×127 mm having the same componentcompositions as those of the tire cases formed under the same conditionsas in the Examples and the Comparative Examples were prepared, andtensile strength, elongation at break, tensile modulus of elasticity,and breaking state were evaluated. The results are shown in Table 9-1.The production method of each of the test pieces, the evaluation method,and the evaluation conditions are as follows.

<Production of Test Pieces>

1. Polyamide-Based Thermoplastic Elastomer

-   -   1) UBESTA, XPA9048 manufactured by Ube Industries, Ltd.        -   (a glass-transition temperature of −6° C., an elastic            modulus of 183 MPa)

2. Polyester-Based Thermoplastic Elastomer

-   -   1) HYTREL 3046 manufactured by Du Pont-Toray Co., Ltd.        -   (a glass-transition temperature of −38° C., an elastic            modulus of 19 MPa)

3. Acid-Modified Polyolefin

-   -   1) ADMER QF551 manufactured by Mitsui Chemicals, Inc.        -   (a glass-transition temperature of −13° C., an elastic            modulus of 694 MPa)    -   2) ADMER QE060 manufactured by Mitsui Chemicals, Inc.        -   (a glass-transition temperature of 4° C., an elastic modulus            of 875 MPa)

4. Olefin-Based Thermoplastic Elastomer Including Polypropylene

-   -   1) PRIME TPO E-2900 (homopolymer) manufactured by Prime Polymer        Co., Ltd.        -   (an elastic modulus of 665 MPa)    -   2) PRIME TPO F-3740 (random polymer) manufactured by Prime        Polymer Co., Ltd.        -   (an elastic modulus of 332 MPa)    -   3) PRIME TPO M142E (block polymer) manufactured by Prime Polymer        Co., Ltd.        -   (an elastic modulus of 39 MPa)    -   4) MILASTOMER-8032 NS (PP/EPDM) manufactured by Mitsui        Chemicals, Inc.        -   (an elastic modulus of 39 MPa)    -   5) MILASTOMER-7030 NS (PP/EPDM) manufactured by Mitsui        Chemicals, Inc.        -   (an elastic modulus of 6.8 MPa)

The thermoplastic elastomers were mixed in a composition (in terms ofmass) shown in Table 9-1 and were kneaded with a twin-screw extruderLABOPLASTOMILL 50 MR manufactured by Toyo Seiki Seisaku-sho, Ltd. toobtain pellets.

Using each of the prepared pellets of the Examples and the ComparativeExamples, injection molding was performed under the following conditionsto obtain test pieces.

For the injection molding, SE30D manufactured by Sumitomo HeavyIndustries, Ltd. was used, the molding temperature was set to from 200°C. to 235° C. and the mold temperature was set to from 50° C. to 70° C.,and a mold of 12.7 mm×127 mm and having a thickness of 1.6 mm was used.

<Evaluation Method>

1. Evaluations of Tensile Strength, Elongation at Break, Tensile Modulusof Elasticity, and Breaking State

Using the test pieces obtained as above, tensile strength, elongation atbreak, tensile modulus of elasticity, and breaking state were evaluatedas follows.

By using Shimadzu Autograph AGS-J (5 KN) manufactured by ShimadzuCorporation, using JIS 5 type dumbbells, and pulling the test pieces ata tensile rate of 200 mm/min, tensile strength, elongation at break,tensile modulus of elasticity, and breaking state of the test pieceswere examined.

TABLE 9-1 Comparative Comparative Example Example Example Example 9-19-1 9-2 9-3 9-4 9-5 9-2 9-6 Polyamide-based thermoplastic elastomerUBESTA 70 70 70 70 70 70 XPA9048 Polyester-based thermoplastic elastomerHYTREL 70 70 3046 Acid-modified olefin QF551 30 15 15 15 15 15 30 15Olefin-based thermoplastic elastomer including polypropylene PRIME 15 15TPO E- 2900 PRIME 15 TPO F- 3740 PRIME 15 TPO M142E MILASTOMER 15 8032NSMILASTOMER 15 7030NS Evaluation Tensile 37 42 39 31 32 30 14 11 strength(MPa) Elongation 545 610 575 500 525 520 500 340 at break (%) Tensile346 340 287 211 200 191 280 110 modulus of elasticity (MPa)

As seen from Table 9-1, it is apparent that the test pieces of Examples9-1 to 9-6 had better impact resistance than the Comparative Example.More specifically, it is considered that when the specific resinaccording to the ninth aspect of the present invention, the other resinand the second thermoplastic elastomer have a hard segment with askeleton that is common to the skeleton constituting the main chain ofthe specific resin according to the ninth aspect of the presentinvention, the second thermoplastic elastomer is dispersed in thespecific resin according to the ninth aspect of the present invention.Accordingly, it is considered that the elastic modulus of the specificresin phase according to the ninth aspect of the present invention isreduced, and impact resistance is increased; therefore, it is consideredthat the entire viscoelasticity of the resin material is reduced andimpact resistance is excellent.

In addition, a drum running test was performed on each of the tiresformed according to the Examples and the Comparative Examples, and allof the tires had no problems in stability during running.

Examples According to Tenth Aspect of the Present Invention

Hereinafter, the tenth aspect of the present invention is described inmore detail using Examples. However, the tenth aspect of the presentinvention is not limited thereto.

First, tires of the Examples and the Comparative Examples were formedaccording to Embodiment 10-2 described above. Here, as for the materialthat forms the tire case, materials described in the following Table10-1 were used. Regarding each of the Examples and the ComparativeExamples, tire performance was examined from evaluation of physicalproperties of the materials.

<Production of Test Pieces>

1. Polyamide-Based Thermoplastic Elastomer

-   -   1) UBESTA, XPA 9048 X1 manufactured by Ube Industries, Ltd.    -   2) UBESTA, XPA 9055 X1 manufactured by Ube Industries, Ltd.

2. Polyester-Based Thermoplastic Elastomer

-   -   1) HYTREL, 5557 manufactured by Du Pont-Toray Co., Ltd.    -   2) HYTREL, 6347 manufactured by Du Pont-Toray Co., Ltd.    -   3) HYTREL, 3046 manufactured by Du Pont-Toray Co., Ltd.

[Production of Pellets]

The elastomers were mixed in a composition (in terms of mass) shown inTable 10-1 and were kneaded by a twin-screw extruder LAB OPLASTOMILL 50MR manufactured by Toyo Seiki Seisaku-sho, Ltd. to obtain pellets. InComparative Examples 10-1 to 10-3, a mixed system was not used, andpellets of polyamide-based thermoplastic elastomers or polyester-basedthermoplastic elastomers were provided.

<Evaluations of Tensile Strength, Elongation at Break, Tensile Modulusof Elasticity, and Tensile Yield Strength>

Injection molding was performed on the produced pellets using SE30Dmanufactured by Sumitomo Heavy Industries, Ltd. by setting a moldingtemperature to from 200° C. to 235° C., setting a mold temperature tofrom 50° C. to 70° C., and using a mold of 12.7 mm×127 mm and having athickness of 1.6 mm to obtain samples.

Each of the samples was punched out, whereby dumbbell-shaped test pieces(No. 5 type test pieces) defined in JISK6251:1993 were produced.

Next, by using Shimadzu Autograph AGS-J (5 KN) manufactured by ShimadzuCorporation and setting a tensile rate to 200 mm/min, tensile modulus ofelasticity, tensile strength, and elongation at break of each of thedumbbell-shaped test pieces were measured.

Regarding the tensile yield strength, tensile yield strengths at 23° C.,85° C., and 105° C. were measured. Here, tensile yield strengths at 23°C. were measured using Shimadzu Autograph AGS-J (5 KN) manufactured byShimadzu Corporation, and tensile yield strengths at 85° C. and 105° C.were measured using Shimadzu Autograph AGS-100 KN manufactured byShimadzu Corporation. The tensile rate was set to 200 mm/min at anytemperature.

The results are shown in the following Table 10-1.

In addition, the relationship between the tensile yield strengths at 23°C., 85° C., and 105° C. and temperatures of Examples 10-1 to 10-6 andComparative Examples 10-1 and 10-2 is shown in FIG. 13. In addition, theslope, the intercept, and the coefficient of determination (R2) of theregression lines (yield strength-temperature lines) perceived from theplot of the temperatures with respect to the tensile yield strengths at23° C., 85° C., and 105° C. of Examples 10-1 to 10-6 and ComparativeExamples 10-1 and 10-2 are shown in Table 10-1.

<Deflection Temperature Under Load>

Injection molding was performed using the produced pellets and usingSE30D manufactured by Sumitomo Heavy Industries, Ltd. by setting amolding temperature to from 200° C. to 235° C., setting a moldtemperature to from 50° C. to 70° C., and using a mold having amulti-purpose test piece shape (JIS K7139, ISO-3167) to obtainmulti-purpose test piece-shaped samples (JIS K7139, ISO-3167) having athickness of 4 mm.

The obtained multi-purpose test pieces were cut and processed to haveshapes of 127 mm×10 mm and having a thickness of 4 mm, the deflectiontemperature under load (ASTM D648) under a load of 0.45 MPa was measuredusing a HDT/VSPT test device (manufactured by Ueshima Seisakusho Co.,Ltd.)

The measurement conditions are as follows.

The test piece was supported at two points of a span between supportpoints of 100 mm, a load of 0.46 MPa was applied to the center partbetween the support points, the periphery of the test piece was filledwith a silicon oil, and temperature was increased at a rate oftemperature increase of 120° C./hr. Temperature when the deformationamount of the test piece had reached 0.2% was measured. The results areshown in Table 10-1.

TABLE 10-1 Comparative Example Example Example Example Example ExampleComparative Comparative Example 10-1 10-1 10-2 10-3 10-4 10-5 10-6Example 10-2 Example 10-3 Polyamide-based elastomer 1) UBESTA XPA 9048100 75 50 75 50 2) UBESTA XPA 9055 75 55 100 Polyester-basedelastomer 1) HYTREL 5557 25 50 100 2) HYTREL 6347 25 50 3) HYTREL 304625 45 Tensile properties 1) Tensile strength 32 37 36 37 40 37 33 41 26(MPa) 2) Elongation at break 400 510 470 510 465 345 295 350 370 (%) 3)Tensile modulus of 183 193 186 220 277 256 172 303 211 elasticity (MPa)Yield strength temperature dependence 1) Tensile yield strength (MPa)(23° C.) 12 12 13 12.5 14.7 13.1 10 16.5 15 (85° C.) 6.1 7.9 8.3 7.8 9.58.5 6.5 9.1 9.5 (105° C.) 5 6.8 6.3 6 7.7 6.3 4.9 7.6 8.4 2) Yieldstrength- temperature line slope 0.0877 0.0641 0.0803 0.0784 0.0850.0809 0.0608 0.1111 0.0824 intercept 13.926 13.448 14.902 14.336 16.6615.041 11.452 18.955 16.82 R2 0.992 0.9988 0.9965 0.9987 0.9998 0.99250.9943 0.9939 0.9936 Thermal deformation temperature Deflectiontemperature 58 59 64 58 73 66 58 78 104 under load (° C.)

As seen from Table 10-1 and FIG. 13, it is understood that in the testpieces produced in each of the Examples, compared to the test piecesproduced in the Comparative Examples, tensile properties were excellent,temperature dependence of tensile yield strength was small, and thusdeflection temperature under load was high. This indicates that the tiremanufactured using the tire case formed using the same thermoplasticresin materials as those of the test pieces of the Examples hasdurability and is less likely to be affected by changes in temperatureenvironment.

Examples According to Eleventh Aspect of the Present Invention

Hereinafter, the eleventh aspect of the present invention is describedin more detail using Examples. However, the eleventh aspect of thepresent invention is not limited thereto.

First, tires of the Examples and the Comparative Examples were formedaccording to Embodiment 11-2 described above. Here, as for the materialthat forms the tire case, materials described in the following Table11-1 were used. Regarding each of the Examples and the ComparativeExamples, tire performance was examined from evaluation of physicalproperties of the materials.

<Production of Test Pieces>

1. Polyamide-Based Thermoplastic Elastomer

-   -   1) UBESTA, XPA 9055 X1 manufactured by Ube Industries, Ltd.

2. Ethylene-Methacrylic Acid Copolymer (for the Comparative Examples)

-   -   1) NUCREL, N035C manufactured by Du Pont-Mitsui Polychemicals        Co., Ltd.    -   2) NUCREL, AN42115C manufactured by Du Pont-Mitsui Polychemicals        Co., Ltd.

3. Ethylene-Acrylate Copolymer (Specific Copolymer)

-   -   1) ELVALOY, 3427AC manufactured by Du Pont-Mitsui Polychemicals        Co., Ltd.    -   2) ELVALOY, 3717AC manufactured by Du Pont-Mitsui Polychemicals        Co., Ltd.

4. Metal Cross-Linked Body of Ethylene-Methacrylic Acid Copolymer(Specific Copolymer: Ionomer)

-   -   1) HIMILAN, 1855Zn manufactured by Du Pont-Mitsui Polychemicals        Co., Ltd.

[Production of Pellets]

The elastomers and each of the copolymers were mixed in a composition(in terms of mass) shown in Table 11-1 and were kneaded by a twin-screwextruder LABOPLASTOMILL 50 MR manufactured by Toyo Seiki Seisaku-sho,Ltd. to obtain pellets. In Comparative Example 11-1, a mixed system wasnot used, and pellets of polyamide-based thermoplastic elastomers wereprovided.

<Evaluations of Tensile Strength, Elongation at Break, Tensile Modulusof Elasticity, and Tensile Yield Strength>

Injection molding was performed using the prepared pellets and usingSE30D manufactured by Sumitomo Heavy Industries, Ltd. by setting amolding temperature to from 200° C. to 240° C., setting a moldtemperature to from 40° C. to 70° C., and using a mold of 12.7 mm×127 mmand having a thickness of 1.6 mm, to obtain test pieces.

Each of the test pieces was punched out, whereby dumbbell-shaped testpieces (No. 5 type test pieces) defined in JISK6251-1993 were prepared.

Next, by using Shimadzu Autograph AGS-J (5 KN) manufactured by ShimadzuCorporation and setting a tensile rate to 200 mm/min, tensile modulus ofelasticity, tensile strength, and elongation at break of each of thedumbbell-shaped test pieces were measured.

Regarding the tensile yield strength, tensile yield strengths at 23° C.,85° C., and 105° C. were measured. Here, tensile yield strengths at 23°C. were measured using Shimadzu Autograph AGS-J (5 KN) manufactured byShimadzu Corporation, and tensile yield strengths at 85° C. and 105° C.were measured using Shimadzu Autograph AGS-100 KN manufactured byShimadzu Corporation. The tensile rate was set to 200 mm/min at anytemperature.

The results are shown in the following Table 11-1.

In addition, the relationship between the tensile yield strengths at 23°C., 85° C., and 105° C. and temperatures of Examples 11-1 to 11-3 andComparative Example 11-1 is shown in FIG. 14. In addition, the slope,the intercept, and the coefficient of determination (R2) of theregression lines (yield strength-temperature lines) perceived from theplot of the temperatures with respect to the tensile yield strengths at23° C., 85° C., and 105° C. of Examples 11-1 to 11-3 and ComparativeExample 11-1 are shown in Table 11-1.

TABLE 11-1 Comparative Comparative Comparative Example Example ExampleExample 11-1 Example 11-2 Example 11-3 11-1 11-2 11-3 Polyamide-basedelastomer 1) UBESTA XPA 9055X1 100 70 70 70 70 70 Ethylene-acrylic acidcopolymer 1) NUCREL N035C 30 2) NUCREL AN42115C 30 Ethylene-acrylatecopolymer 1) ELVALOY 3427AC 30 2) ELVALOY 3717AC 30 Ionomer of ethylene-methacrylic acid copolymer 1) HIMILAN 1855Zn 30 Tensile properties 1)Tensile strength (MPa) 41 27 36 22 29 30 2) Elongation at break (%) 350320 445 250 400 260 3) Tensile modulus of 303 238 266 208 222 253elasticity (MPa) Yield strength temperature dependence 1) Tensile yieldstrength (MPa) (23° C.) 16.5 13 13.2 12.5 13 13 (85° C.) 9.1 6.5 6.7 77.3 6.7 (105° C.) 7.6 4 4.2 5.2 5.2 5 2) Yield strength- temperatureline slope 18.955 15.543 15.743 14.549 15.2 15.228 intercept 0.11110.1085 0.1086 0.0889 0.0944 0.0985 R2 0.9939 0.9987 0.9987 1 0.99930.9989

As seen from Table 11-1 and FIG. 14, it is understood that in the testpieces produced in each of the Examples, compared to the test piecesproduced in Comparative Example 11-1, the slope of the yieldstrength-temperature line was small, tensile properties were excellent,and temperature dependence of tensile yield strength was small. Thisindicates that the tire manufactured using the tire case formed usingthe same thermoplastic resin materials as those of the test pieces ofthe Examples has durability and is less likely to be affected by changesin temperature environment. In addition, it is perceived that in thetest pieces produced in each of the Examples, compared to the testpieces produced in the Comparative Examples, elastic modulus is low,flexibility is provided, and impact resistance is excellent.

In addition, a drum running test was performed on each of the tiresformed using the thermoplastic resin materials of each of the Examplesand the Comparative Examples, and all of the tires had no problems instability during running.

Examples According to Twelfth Aspect of the Present Invention

Hereinafter, the twelfth aspect of the present invention is described inmore detail using Examples. However, the twelfth aspect of the presentinvention is not limited thereto.

First, tires of the Examples and the Comparative Examples were formedaccording to Embodiment 12-2 described above. Here, as for the materialthat forms the tire case, materials described in the following Table12-1 were used. Regarding each of the Examples and the ComparativeExamples, tire performance was examined from evaluation of physicalproperties of the materials.

<Production of Test Pieces>

1. Polyamide-Based Thermoplastic Elastomer

-   -   UBESTA, XPA 9055 X1 manufactured by Ube Industries, Ltd.

2. Ethylene-Methacrylic Acid Copolymer (Specific Copolymer)

-   -   NUCREL, N035C manufactured by Du Pont-Mitsui Polychemicals Co.,        Ltd.    -   NUCREL, AN42115C manufactured by Du Pont-Mitsui Polychemicals        Co., Ltd.

3. Ethylene-Acrylate Ethyl Ester Copolymer (Specific Acid-ModifiedCopolymer)

-   -   HPR, AR2011 manufactured by Du Pont-Mitsui Polychemicals Co.,        Ltd.

[Production of Pellets]

The elastomers and the ethylene-acrylate copolymers were mixed in acomposition (in terms of mass) shown in Table 12-1 and were kneaded by atwin-screw extruder LABOPLASTOMILL 50 MR manufactured by Toyo SeikiSeisaku-sho, Ltd. to obtain pellets. In Comparative Example 12-1, amixed system was not used, and pellets of polyamide-based thermoplasticelastomers were provided.

<1. Evaluations of Tensile Strength, Elongation at Break, TensileModulus of Elasticity, and Breaking State>

Injection molding was performed using the prepared pellets and usingSE30D manufactured by Sumitomo Heavy Industries, Ltd. by setting amolding temperature to from 200° C. to 240° C., setting a moldtemperature to from 50° C. to 70° C., and using a mold of 12.7 mm×127 mmand having a thickness of 1.6 mm, to obtain test pieces.

Each of the test pieces was punched out, whereby dumbbell-shaped testpieces (No. 5 type test pieces) defined in JISK6251-1993 were prepared.

Regarding the pellets in Comparative Example 12-2, the injection moldingcould not be performed under the above-mentioned injection moldingconditions. Therefore, by using an electrothermal press manufactured byKodaira Seisakusho Co., Ltd., thermal pressing was performed by heatingthe pellets at 200° C. and 12 MPa for 5 minutes to obtain test pieceseach of 120 mm×120 mm and having a thickness of 2 mm.

Next, by using Shimadzu Autograph AGS-J (5 KN) manufactured by ShimadzuCorporation and setting a tensile rate to 200 mm/min, tensile modulus ofelasticity, tensile strength, elongation at break, and breaking state ofeach of the dumbbell-shaped test pieces were examined. The results areshown in Table 12-1.

The breaking state was evaluated by visually observing a cross-sectionof the test piece based on the following evaluation criteria.

—Evaluation Criteria—

O: the test piece was broken due to ductile fracture.

Δ: the test piece was broken due to laminar-shaped fracture.

x: the test piece was broken due to brittle fracture.

<2. Evaluation of Fluidity [MFR (g/10 Min, 230° C.)]>

A load of 21.18 N, 49.03 N, or 98.07 N was applied to each of thepellets of the Examples and the Comparative Examples using a semi-automelt indexer 2A type manufactured by Toyo Seiki Seisaku-sho, Ltd. basedon the ASTM A1238 (B method) to measure fluidity (MFR). The results areshown in Table 12-1. Measurement was started from a small load (21.18N), and in a case in which MFR could not be measured under thiscondition, a higher load was applied for measurement. After startingmeasurement, those for which measurement did not start even after 3minutes elapsed were indicated by “-” in the table.

TABLE 12-1 Comparative Comparative Comparative Comparative ExampleExample Example 12-1 Example 12-2 Example 12-3 Example 12-4 12-1 12-2Polyamide-based thermoplastic elastomer UBESTA XPA 100 70 70 70 70 709055X1 Acid-modified body of ethylene- acrylate copolymer HPR AR2011 3015 10 Ethylene- methacrylic acid copolymer NUCREL N035C 30 15 20 NUCREL30 AN42115C Tensile properties 1) Tensile 41 17 27 36 29 35 strength(MPa) 2) Elongation at 350 225 320 445 210 290 break (%) 3) Tensile 303180 238 266 239 258 modulus of elasticity (MPa) 4) Breaking state ◯ ◯◯-Δ Δ ◯ ◯ Fluidity MFR load 20.1 — 18.87 27.73 — — 21.18 N MFR load — —4.18 49.03 N MFR load — 8.22 98.07 N

As seen from Table 12-1, regarding the test pieces produced in each ofthe Examples, compared to the test pieces produced in the ComparativeExamples, elastic modulus was small, and flexibility was provided.Therefore, it is perceived that when a tire is formed using the samethermoplastic resin materials as those of the test pieces, the tire hasexcellent impact resistance. Moreover, from the evaluation results ofthe breaking states, the test pieces produced in the Examples weresubjected to ductile fracture. Therefore, it is assumed that the tireformed using the same thermoplastic resin materials as those of the testpieces is less likely to burst and break even when the tire is damaged,and thus fracture property is excellent.

In addition, all the test pieces produced in each of the Examples hadexcellent fluidity. Therefore, it is perceived that when the samethermoplastic resin materials as those of the test piece are used,injection molding is performed easily, tires may be efficientlymanufactured, and productivity of tires may be enhanced.

In addition, a drum running test was performed on each of the tiresformed using the thermoplastic resin materials having the samecomposition as that of each of the test pieces of the Examples and theComparative Examples, and all of the tires had no problems in stabilityduring running.

Examples According to Thirteenth Aspect of the Present Invention

Hereinafter, the thirteenth aspect of the present invention is describedin more detail using Examples. However, the thirteenth aspect of thepresent invention is not limited thereto.

First, tires of the Examples and the Comparative Examples were formedaccording to Embodiment 13-2 described above. Here, as for the materialthat forms the tire case, materials described in the following Table13-1 and 13-2 were used. Regarding each of the Examples and theComparative Examples, tire performance was examined from evaluation ofphysical properties of the materials.

[Production of Test Pieces]

1. Polyamide-Based Thermoplastic Elastomer

-   -   UBESTA, XPA 9055 X1 manufactured by Ube Industries, Ltd.

2. Rubber

-   -   1) Butadiene rubber (BR)    -   2) Styrene-butadiene copolymer rubber    -   3) Acrylonitrile-butadiene copolymer rubber (NBR)

BR, SBR, and NBR were all extruded with a single-screw extruder to formpellets and used.

3. Rubber-Affinity Thermoplastic Elastomer

-   -   1) Acid-modified α-olefin-based thermoplastic elastomer        -   TOUGHMER, MH7010 manufactured by Mitsui Chemicals, Inc.    -   2) Acid-modified hydrogenated polystyrene-based thermoplastic        elastomer (SEBS)        -   TUFTEC, M1913 manufactured by Asahi Kasei Corporation

4) Vulcanized Rubber (DV1 to DV3)

After, using each of the rubbers of BR, SBR, and NBR, the kinds andamounts of components shown in the following Table 13-1 were mixed andwere kneaded with a Banbury mixer to form sheet shapes, using two rolls,and the resultants were extruded using a single-screw extruder to formpellets for use.

In addition, the obtained rubber was cross-linked during kneading withthe polyamide-based thermoplastic elastomer in the twin-screw extruder.

TABLE 13-1 Compounding ingredient DV1 DV2 DV3 BR 100 SBR 100 NBR 100Normal sulfur (5% 0.525 0.525 0.525 oil treated) N-N′-diphenyl 2 2 2methane bismaleimide Accelerator CZ 1.5 1.5 1.5 Accelerator TS 1 1 1stearic acid 2 2 2 Zinc oxide II (ZnO) 5 5 5

Details of normal sulfur, accelerator CZ, and accelerator TS in Table13-1 are as follows.

Normal sulfur . . . normal sulfur manufactured by Tsurumi ChemicalIndustry Co., Ltd.

Vulcanization accelerator CZ . . . “NOCCELER CZ” manufactured by OuchiShinko Chemical Industrial Co., Ltd.

-   -   (N-cyclohexyl-2-benzothiazolesulfenamide)

Accelerator TS “NOCCELER TS” manufactured by Ouchi Shinko ChemicalIndustrial Co., Ltd.

-   -   (tetramethylthiuram monosulfide)

[Production of Pellets of Thermoplastic Resin Material]

The elastomers were mixed in a composition (in terms of mass) shown inTable 13-2 and were kneaded by a twin-screw extruder LAB OPLASTOMILL 50MR manufactured by Toyo Seiki Seisaku-sho, Ltd. to obtain pellets. InComparative Example 13-1, a mixed system was not used, and pellets ofpolyamide-based thermoplastic elastomers were provided.

1. Evaluations of Tensile Strength, Elongation at Break, and TensileModulus of Elasticity

Injection molding was performed using the produced pellets and usingSE30D manufactured by Sumitomo Heavy Industries, Ltd. by setting amolding temperature to from 200° C. to 235° C., setting a moldtemperature to from 50° C. to 70° C., and using a mold of 12.7 mm×127 mmand having a thickness of 1.6 mm, to obtain test pieces.

Each of the test pieces was punched out, whereby dumbbell-shaped testpieces (No. 5 type test pieces) defined in JISK6251:1993 were prepared.

Next, by using Shimadzu Autograph AGS-J (5 KN) manufactured by ShimadzuCorporation and setting a tensile rate to 200 mm/min, tensile modulus ofelasticity, tensile strength, and elongation at break of each of thedumbbell-shaped test pieces were measured.

The results are shown in the following Table 13-2.

2. Measurement of Tan δ

By using a dynamic viscoelasticity measurement test machine “ARES III”manufactured by Rheometric Scientific, Inc., a loss tangent (tan δ) wasmeasured at a temperature of 30° C., a measurement frequency of 20 Hz,and a dynamic strain of 1%.

The tensile strength, the elongation at break, the tensile modulus ofelasticity, and the tan δ of the test pieces of the Examples and theComparative Examples are shown in Table 13-2.

TABLE 13-2 Comparative Example Example Example Example Example ExampleExample Example Example 13-1 13-1 13-2 13-3 13-4 13-5 13-6 13-7 13-8Polyamide-based therm oplastic elastomer UBESTA XPA 100 70 70 70 70 7070 70 70 9055X1 Rubber BR 30 15 SBR 30 15 NBR 30 Rubber-affinitythermoplastic elastomer Acid-modified α- 15 olefin Acid-modified SEBS 15Vulcanized rubber DV1 30 DV2 30 DV3 30 Tensile properties Tensilestrength 41 25 33 25 31 26 29 28 33 (MPa) Elongation at break 350 320325 330 260 325 295 315 320 (%) Tensile modulus of 303 224 216 193 199201 241 209 221 elasticity (MPa) tanδ 0.121 0.091 0.089 0.097 0.1070.102 0.106 0.116 0.108

As seen from Table 13-2, it is understood that in the test piecesproduced in each of the Examples, compared to the test pieces producedin the Comparative Examples, tensile modulus of elasticity was low, andsufficient flexibility was provided. This indicates that the tiremanufactured using the tire case formed using the same thermoplasticresin materials as those of the test pieces described in the Exampleshas excellent impact resistance and has durability, for example, thetire is less likely to break even when the tire comes into contact witha curb. In addition, all the test pieces of the Examples have lower tanδ than those of the test pieces of the Comparative Examples. Therefore,it is perceived that the rolling resistance of the tire produced usingthe same thermoplastic resin materials as those of the test piecesdescribed in the Examples is suppressed, and when the tire is applied toa vehicle, low fuel consumption may be exhibited.

In addition, a drum running test was performed on each of the tiresformed using the thermoplastic resin materials of each of the Examplesand the Comparative Examples, and all of the tires had no problems instability during running.

The following invention is included in the first aspect of the presentinvention.

[1-1] A tire including at least a circular tire frame formed of athermoplastic resin material,

the tire including a reinforcing cord member that is wound around theouter circumference of the tire frame in the circumferential directionto form a reinforcing cord layer, and

the thermoplastic resin material including at least a polyamide-basedthermoplastic elastomer.

[1-2] The tire as described in [1-1], wherein the reinforcing cord layeris configured to include a resin material.

[1-3] The tire as described in [1-1] or [1-2], wherein the melting pointof the thermoplastic resin material including the polyamide-basedthermoplastic elastomer is 100° C. to 250° C.

[1-4] The tire as described in any one of [1-1] to [1-3], wherein thecontent ratio of the polyamide-based thermoplastic elastomer in thethermoplastic resin material is 50 mass % to 100 mass %.

The following invention is included in the second aspect of the presentinvention.

[2-1] A tire including at least a circular tire frame formed of athermoplastic resin material,

the tire including reinforcing a cord member that is wound around theouter circumference of the tire frame in the circumferential directionto form a reinforcing cord layer, and

the thermoplastic resin material including at least a polyamide-basedthermoplastic elastomer and an elastomer other than the polyamide-basedthermoplastic elastomer.

[2-2] The tire as described in [2-1], wherein the reinforcing cord layeris configured to include a resin material.

[2-3] The tire as described in [2-1] or [2-2], wherein the mass ratio(x:y) of the polyamide-based thermoplastic elastomer (x) and the otherelastomer (y) in the thermoplastic resin is from 95:5 to 60:40.

[2-4] The tire as described in any one of [2-1] to [2-3], wherein theother elastomer is any one selected from a polyurethane-basedthermoplastic elastomer, a polyolefin-based thermoplastic elastomer, apolystyrene-based thermoplastic elastomer, or a polyester-basedthermoplastic elastomer.

The following invention is included in the third aspect of the presentinvention.

[3-1] A tire including at least a circular tire frame formed of athermoplastic resin material,

the thermoplastic resin material including a polyamide-basedthermoplastic elastomer and an acid-modified elastomer obtained byacid-modifying a thermoplastic elastomer other than the polyamide-basedthermoplastic elastomer, or a mixture of a thermoplastic elastomer otherthan the polyamide-based thermoplastic elastomer and an acid-modifiedelastomer obtained by acid-modifying the elastomer other than thepolyamide-based thermoplastic elastomer.

[3-2] The tire as described in [3-1], wherein the acid value of thethermoplastic resin material is equal to or greater than 0.1 mg-CH₃ONa/gbut less than 2.2 mg-CH₃ONa/g.

[3-3] The tire as described in [3-1] or [3-2], wherein the ratio of themass of the polyamide-based thermoplastic elastomer and the total massof the thermoplastic elastomer other than the polyamide-basedthermoplastic elastomer and the acid-modified elastomer (the mass of thepolyamide-based thermoplastic elastomer:the total mass of theacid-modified elastomer and the thermoplastic elastomer other than thepolyamide-based thermoplastic elastomer) in the thermoplastic resinmaterial is from 90:10 to 60:40.

[3-4] The tire as described in any one of [3-1] to [3-3], wherein thecontent of the polyamide-based thermoplastic elastomer in thethermoplastic resin material is 55 mass % to 95 mass %.

[3-5] A method for producing a tire, the method including:

a tire frame piece forming step of forming a tire frame piece forconstituting a portion of a circular tire frame, using a thermoplasticresin material including at least: a polyamide-based thermoplasticelastomer; and an acid-modified elastomer obtained by acid-modifying athermoplastic elastomer other than the polyamide-based thermoplasticelastomer, or a mixture of a thermoplastic elastomer other than thepolyamide-based thermoplastic elastomer and an acid-modified elastomerobtained by acid-modifying the elastomer other than the polyamide-basedthermoplastic elastomer; and

a tire frame piece bonding step of forming the time frame by fusing twoor more of the tire frame pieces, which make a pair, by applying heat tobonding sections of the tire frame pieces.

[3-6] The method for producing a tire as described in [3-5], wherein theacid value of the thermoplastic resin material is equal to or greaterthan 0.1 mg-CH₃ONa/g but less than 2.2 mg-CH₃ONa/g.

[3-7] The method for producing a tire as described in [3-6], wherein thetire frame piece forming step includes a step of injection molding usingthe thermoplastic resin material.

The following invention is included in the fourth aspect of the presentinvention.

[4-1] A tire including a circular tire frame formed of a thermoplasticresin material,

the thermoplastic resin material including a thermoplastic elastomerincluding a hard segment and a soft segment in a molecule thereof, andneedle-shaped crystal grains having a fiber length of 1 μm to 500 μm anda fiber diameter of 0.01 μm to 10.0 μm.

[4-2] The tire as described in [4-1], wherein the content of theneedle-shaped crystal grains relative to the total mass of thethermoplastic resin material is in the range of 0.1 mass % to 10 mass %.

[4-3] The tire as described in [4-1] or [4-2], wherein the needle-shapedcrystal grains are inorganic particles selected from the groupconsisting of metal oxides, metal nitrides, metal carbonates, metalsilicates, metal titanates, metal sulfates, and metal borates.

[4-4] The tire as described in any one of [4-1] to [4-3], wherein thethermoplastic elastomer is a thermoplastic elastomer selected from apolyamide-based thermoplastic elastomer, a polyester-based thermoplasticelastomer, or a polystyrene-based thermoplastic elastomer.

The following invention is included in the fifth aspect of the presentinvention.

[5-1] A tire including at least a circular tire frame formed of a resinmaterial,

the resin material including a thermoplastic elastomer including a hardsegment and a soft segment in a molecule thereof, and a resin having aglass transition temperature that is higher than the glass transitiontemperature of the hard segment.

[5-2] The tire as described in [5-2], wherein the resin has a glasstransition temperature that is higher, by 20° C. or more, than the glasstransition temperature of the hard segment of the thermoplasticelastomer.

[5-3] The tire as described in [5-1] or [5-2], wherein a mass ratio(x+y:z) of the soft segment (z) of the thermoplastic elastomer withrespect to the total (x+y) of the hard segment (x) of the thermoplasticelastomer and the resin (y) is 10:90 to 90:10.

[5-4] The tire as described in any one of [5-1] to [5-3], wherein thethermoplastic elastomer is at least one selected from a polyamide-basedthermoplastic elastomer or a polyester-based elastomer.

[5-5] The tire as described in any one of [5-1] to [5-4], wherein theresin is at least one selected from polyphenylene ether, polyphenylenesulfide, polyethylene terephthalate, polybutylene terephthalate,polyethylene naphthalate, polybutylene naphthalate, polytrimethyleneterephthalate, polycarbonate or polyarylate.

The following invention is included in the sixth aspect of the presentinvention.

[6-1] A tire including a circular tire frame formed of a thermoplasticresin material, the tire frame having a volume resistivity in the rangeof 1.0×10⁶ to 1.0×10¹⁰.

[6-2] The tire as described in [6-1], wherein the tire frame contains anantistatic material.

[6-3] The tire as described in [6-1] or [6-2], wherein the thermoplasticresin material includes a thermoplastic elastomer.

[6-4] The tire as described in [6-2] or [6-3], wherein the antistaticmaterial is a phosphoric acid ester-based ion conductor.

The following invention is included in the seventh aspect of the presentinvention.

[7-1] A tire including at least a circular tire frame formed of athermoplastic resin material,

the thermoplastic resin material including a thermoplastic elastomerincluding a hard segment and a soft segment in a molecule thereof, and aresin which is other than the thermoplastic elastomer and is of the samekind as the hard segment.

[7-2] The tire as described in [7-1], wherein the elastic modulus of theresin is 100 MPa or greater.

[7-3] The tire as described in [7-1] or [7-2], wherein the mass ratio ofthe thermoplastic elastomer and the resin (thermoplasticelastomer:resin) is from 95:5 to 50:50.

[7-4] The tire as described in any one of [7-1] to [7-3], wherein thecontent of the thermoplastic elastomer in the thermoplastic resinmaterial is 50 mass % to 95 mass %.

[7-5] The tire as described in any one of [7-1] to [7-4], wherein thethermoplastic elastomer is a polyamide-based thermoplastic elastomer,and the resin is a polyamide-based resin.

The following inventions are included in the present invention relatedto the eighth aspect.

[8-1] A tire including at least a circular tire frame formed of a resinmaterial,

the resin material including at least a thermoplastic elastomer, and aresin which is other than the thermoplastic elastomer, has a glasstransition temperature of 20° C. or lower and has an elastic moduluslarger than the elastic modulus of the thermoplastic elastomer.

[8-2] The tire as described in [8-1], wherein the resin is anacid-modified resin.

[8-3] The tire as described in [8-2], wherein the acid-modified resin isat least one selected from acid-modified polyolefin resins.

[8-4] The tire as described in [8-2] or [8-3], wherein the resinmaterial further includes a resin which is other than the thermoplasticelastomer and is not acid-modified.

[8-5] The tire as described in [8-4], wherein the resin that is notacid-modified is at least one selected from polyolefin resins.

[8-6] The tire as described in [8-1], wherein the resin is a resin thatis not acid-modified.

[8-7] The tire as described in [8-6], wherein the resin that is notacid-modified is at least one selected from polyolefin resins.

[8-8] The tire as described in any one of [8-1] to [8-7], wherein thethermoplastic elastomer is at least one selected from a polyamide-basedthermoplastic elastomer, a polyester-based thermoplastic elastomer, apolystyrene-based thermoplastic elastomer or a polyurethane-basedthermoplastic elastomer.

The following invention is included in the ninth aspect of the presentinvention.

[9-1] A tire including at least a circular tire frame formed of a resinmaterial,

the resin material including at least a first thermoplastic elastomer, aresin which is other than the first thermoplastic elastomer and has aglass transition temperature of 20° C. or lower, and a secondthermoplastic elastomer which is other than the first thermoplasticelastomer and has a hard segment of the same kind as the resin.

[9-2] The tire as described in [9-1], wherein the resin is anacid-modified resin.

[9-3] The tire as described in [9-2], wherein the acid-modified resin isat least one selected from acid-modified polyolefin resins.

[9-4] The tire as described in [9-3], wherein the second thermoplasticelastomer is an olefin-based thermoplastic elastomer.

[9-5] The tire as described in any one of [9-2] to [9-4], wherein theresin material further includes a resin that is other than the firstthermoplastic elastomer and the second thermoplastic elastomer and isnot acid-modified.

[9-6] The tire as described in [9-5], wherein the resin that is notacid-modified is at least one selected from olefin resins.

[9-7] The tire as described in [9-6], wherein the acid-modified resin isan acid-modified polyolefin resin, the resin that is not acid-modifiedis polypropylene, and the second thermoplastic elastomer is anolefin-based thermoplastic elastomer containing polypropylene.

[9-8] The tire as described in any one of [9-1] to [9-7], wherein thefirst thermoplastic elastomer is at least one selected from apolyamide-based thermoplastic elastomer, a polyester-based thermoplasticelastomer, a polyurethane-based thermoplastic elastomer, or apolystyrene-based thermoplastic elastomer.

The following invention is included in the tenth aspect of the presentinvention.

[10-1] A tire including at least a circular tire frame formed of athermoplastic resin material,

the tire including a reinforcing cord member that is wound around theouter circumference of the tire frame in a circumferential direction toform a reinforcing cord layer, and

the thermoplastic resin material including at least a polyamide-basedthermoplastic elastomer and a polyester-based thermoplastic elastomer.

[10-2] The tire as described in [10-1], wherein the reinforcing cordlayer is configured to include a resin material.

[10-3] The tire as described in [10-1] or [10-2], wherein the mass ratio(x:y) of the polyamide-based thermoplastic elastomer (x) and thepolyester thermoplastic elastomer (y) in the thermoplastic resin is from95:5 to 50:50.

[10-4] The tire as described in any one of [10-1] to [10-3], wherein thetotal content of the polyamide-based thermoplastic elastomer and thepolyester-based thermoplastic elastomer in the thermoplastic resinmaterial is 50 mass % to 100 mass %.

The following invention is included in the eleventh aspect of thepresent invention.

[11-1] The tire of the present invention is a tire including at least acircular tire frame formed of a thermoplastic resin material,

the thermoplastic resin material including a polyamide-basedthermoplastic elastomer and at least one copolymer of anolefin-(meth)acrylate copolymer or a metal crosslinked product of anolefin-(meth)acrylic acid copolymer.

[11-2] The tire as described in [11-1], wherein the mass ratio (x: y) ofthe polyamide-based thermoplastic elastomer (x) and the copolymer (y) isfrom 95:5 to 50:50.

[11-3] The tire as described in [11-1] or [11-2], wherein the totalcontent of the polyamide-based thermoplastic elastomer and the copolymerin the thermoplastic resin material is 50 mass % to 100 mass %.

[11-4] The tire as described in any one of [11-1] to [11-3], wherein theolefin-(meth)acrylate copolymer is an ethylene-(meth)acrylate copolymer.

[11-5] The tire as described in any one of [11-1] to [11-4], wherein themetal crosslinked product of the olefin-(meth)acrylic acid copolymer isa metal crosslinked product of an ethylene-(meth)acrylic acid copolymer.

The following invention is included in the twelfth aspect of the presentinvention.

[12-1] A tire including at least a circular tire frame formed of athermoplastic resin material,

the thermoplastic resin material including a polyamide-basedthermoplastic elastomer, an olefin-(meth)acrylic acid copolymer, and anacid-modified copolymer obtained by acid-modifying anolefin-(meth)acrylate copolymer.

[12-2] The tire as described in [12-1], wherein the mass ratio (x:y+z)of the polyamide-based thermoplastic elastomer (x), theolefin-(meth)acrylic acid copolymer (y), and the acid-modified copolymer(z) is from 95:5 to 50:50.

[12-3] The tire as described in [12-1] or [12-2], wherein the totalcontent of the polyamide-based thermoplastic elastomer, theolefin-(meth)acrylic acid copolymer, and the acid-modified copolymer inthe thermoplastic resin material is 50 mass % to 100 mass %.

[12-4] The tire as described in any one of [12-1] to [12-3], wherein theolefin-(meth)acrylic acid copolymer is an ethylene-(meth)acrylic acidcopolymer, and the acid-modified copolymer is an acid-modified copolymerobtained by acid-modifying an ethylene-(meth)acrylate copolymer.

[12-5] A method for producing a tire, the method including:

a tire frame piece forming step of forming a tire frame piece forconstituting a portion of a circular tire frame, using a thermoplasticresin material including at least a polyamide-based thermoplasticelastomer, an olefin-(meth)acrylic acid copolymer, and an acid-modifiedcopolymer obtained by acid-modifying an olefin-(meth)acrylate copolymer;and

a tire frame piece bonding step of forming the tire frame by fusing twoor more of the tire frame pieces, which make a pair, by applying heat tobonding sections of the tire frame pieces.

[12-6] The method for producing a tire as described in [12-5], whereinthe olefin-(meth)acrylic acid copolymer is an ethylene-(meth)acrylicacid copolymer, and the acid-modified copolymer is an acid-modifiedcopolymer obtained by acid-modifying an ethylene-(meth)acrylatecopolymer.

The following invention is included in the thirteenth aspect of thepresent invention related to the thirteenth aspect.

[13-1] A tire including at least a circular tire frame formed of athermoplastic resin material,

the tire including a reinforcing cord member that is wound around theouter circumference of the tire frame in the circumferential directionto form a reinforcing cord layer, and

the thermoplastic resin material including at least a polyamide-basedthermoplastic elastomer and a rubber.

[13-2] The tire as described in [13-1], wherein the thermoplastic resinmaterial further includes a thermoplastic elastomer having high affinityfor the rubber.

[13-3] The tire as described in [13-1] or [13-2], wherein thereinforcing cord layer is configured to include a resin material.

[13-4] The tire as described in any one of [13-1] to [13-3], wherein themass ratio (x: y) of the polyamide-based thermoplastic elastomer (x) andthe rubber (y) in the thermoplastic resin material is from 95:5 to50:50.

[13-5] The tire as described in [13-2] or [13-3], wherein the mass ratio(x:y+z) of the polyamide-based thermoplastic elastomer (x), the rubber(y), and the thermoplastic elastomer having high affinity for the rubber(z) in the thermoplastic resin material is from 95:5 to 50:50.

[13-6] The tire as described in any one of [13-1] to [13-4], wherein thetotal content of the polyamide-based thermoplastic elastomer and therubber in the thermoplastic resin material is 50 mass % to 100 mass %.

[13-7] The tire as described in [13-2], [13-3] or [13-5], wherein thetotal content of the polyamide-based thermoplastic elastomer, therubber, and the thermoplastic elastomer having high affinity for therubber in the thermoplastic resin material is 50 mass % to 100 mass %.

The disclosures of Japanese Patent Application Nos. 2010-188918,2010-188919, 2010-188922, 2010-188902, 2010-188923, 2010-188901,2010-203676, 2010-188900, 2010-188915, 2010-188903, 2010-203732,2010-258041, 2010-258040, and 2011-183311 are incorporated herein byreference.

All publications, patent applications, and technical standards mentionedin this specification are herein incorporated by reference to the sameextent as if each individual publication, patent application, ortechnical standard was specifically and individually indicated to beincorporated by reference.

1. A tire comprising at least a circular tire frame formed of athermoplastic resin material, the thermoplastic resin material includinga polyamide-based thermoplastic elastomer, and an acid-modifiedelastomer obtained by acid-modifying a thermoplastic elastomer otherthan the polyamide-based thermoplastic elastomer, or a mixture of athermoplastic elastomer other than the polyamide-based thermoplasticelastomer and an acid-modified elastomer obtained by acid-modifying theelastomer other than the polyamide-based thermoplastic elastomer.
 2. Thetire according to claim 1, wherein the acid value of the thermoplasticresin material is equal to or greater than 0.1 mg-CH₃ONa/g but less than2.2 mg-CH₃ONa/g.
 3. The tire according to claim 1, wherein the ratio ofthe mass of the polyamide-based thermoplastic elastomer and the totalmass of the thermoplastic elastomer other than the polyamide-basedthermoplastic elastomer and the acid-modified elastomer (the mass of thepolyamide-based thermoplastic elastomer:the total mass of theacid-modified elastomer and the thermoplastic elastomer other than thepolyamide-based thermoplastic elastomer) in the thermoplastic resinmaterial is from 90:10 to 60:40.
 4. The tire according to claim 1,wherein the content of the polyamide-based thermoplastic elastomer inthe thermoplastic resin material is 55 mass % to 95 mass %.